# Substance Abuse

A radioactive substance has a half-life of 4 days. Suppose we have 800 mg of this substance. a) Find the equation of the mass remaining after t days. Use the exact value for k not a decimal approximation. b) Rounding your answer to the nearest tenth of a mg, find the mass ...

Math
Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...

math
Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...

Math
Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...

Math
A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...

Math
A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...

math
Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...

science
The type of heat transfer called convection happens as a result of: a. electromagnetic waves b. the direct contact of particles in a substance c. the actual motion of a fluid in the form of currents d. All of the above I think it's C.

chemistry
Based upon the intermolecular forces present, rank the following substances according to the expected boiling point for the substance: MgF2, H2O, HCl, N2

science
PLEASE HELP GUYS An ideal gas for which Cv = 3R/2 is the working substance of a Carnot engine. During the isothermal expansion, the volume doubles. The ratio of the final volume to the initial volume in the adiabatic expansion is 5.7. The work output of the engine is 9 x 105 J...

science
An ideal gas for which Cv = 3R/2 is the working substance of a Carnot engine. During the isothermal expansion, the volume doubles. The ratio of the final volume to the initial volume in the adiabatic expansion is 5.7. The work output of the engine is 9 x 105 J in each cycle. ...

Biology (fetal pig)
What substance passes through the glottis? [Is it Air??] What substances passes through the esophagus? [I don't know if this is food] please help. thanks

Chemistry
I got think I got the following questions almost figured, but I just want someone to make sure that I am correct. 1) The whole experiment involves using the ideal gas law to predict the molar mass of an unknown liquid. The formula is molar mass of liquid = gR(0.0821)T(...

chemistry
A solution is made with 2.0 g of substance that cause the temperature of 75.0 g of water to decrease from 23.1 C to 18.7 C. The specific heat of water is 4.18 J/g C.

Science asap thankies :)
What would a permanently magnetic substance be called? I cant remember what my teacher called it, it was a short first word then magnet.. sorry and thanks!

Statistics
Twelve different video games showing substance use were observed and the duration times of game play ( in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. use the data to construct a 95% ...

science
what is the substance that melts at 10°C?

scholarship essay edit
can someone edit this? Throughout my life’s journey, I have come to attain two true passions - the first one being English studies. Since the very dawn of childhood, I have been known to bleed the calligraphic content of Gary Soto's brilliant poetry and breathe the splendor ...

TO: DrBob222 science
1. Write the chemical formula for each of the following acids: a.) hydrocyanic acid b.) oxalic acid c.) chlorous acid d.) nitric acid 2. Write the acid name or chemical formula for each of the following: a.) HBr b.) sulfurous acid c.) HClO4 D.) phosphoric acid 3. First ...

Physical Science
When 8 kcal of heat is added to 2.4 kg of a substance, its temperature increases 23 C°. What is the specific heat of the substance?

Physical Science 9
a substance made of two or more elements chemically combined in a set ratio or proportion is called what

Science
a substance made of two or more elements chemically combined in a set ratio or proportion is called what

science
One property used to broadly classify elements is malleability. If a substance is malleable, it can be hammered, shaped, and flattened without shattering. Which group of elements has this property? A. Metals B. Metalloids C. Nonmetals D. Noble gases

science
3. A section of the Periodic Table of the Elements is shown. Based on the positions of the elements, the two elements that have the most similar chemical properties are — A. calcium and scandium B. calcium and titanium C. titanium and vanadium D. magnesium and calcium 4. One...

PLS HELP ASAP 1 SUPER HARD & ANNOYING QUESTION
Use the diagram to answer question 13. so substance A looks like a row of three little circles on the top and bottom all organized (total six dots). substance b is all clumped together circles and is disorganized. 13. How can substance A and B be compared? Choose all that ...

Chemistry Urgent
A calorimeter contains 32.0mL of water at 13.0∘C . When 2.30g of X (a substance with a molar mass of 82.0g/mol is added, it dissolves via the reaction X(s)+H2O(l)¨X(aq) and the temperature of the solution increases to 30.0∘C . Calculate the enthalpy change, ƒ¢...

Science help
A student combined water, sugar, and salt into a beaker. Which of the following statements are true? a. The individual substances can be separated by physical means.** b. The individual substances cannot be separated by physical means. c. A new substance is made of two or more...

Chemistry
A 2.6 g of a substance that looks like gold needed 9.4 J of heat energy to raise its temperature from 20 to 38 ºC. Is the metal pure gold?

I only have a couple questions left but I want to be sure that my answers are correct so can someone please help me by checking my answers and if they are wrong can someone please let me know? Thank you! Question Number 1: A freshwater marsh is a type of ecosystem. Grasses, ...

Science
If the melting point of a substance is -39C, has the substance melted at 20C?

chemistry
Hello, a few questions: Thanks so much! 1. The heat capacities of titanium and water are 0.522 J g-1 K-1 and 4.184 J g-1 K-1, respectively. What is the final temperature of the titanium-water mixture if a 175.0-g sample of titanium, initially at 90.0oC, is added to 50.0 g of ...

Chemistry
If say 70 mL of water is heated vs 100 mL of water, would the temperature be different or does the amount of the substance not make a difference on the temperature Thanks!

science
1.   Which statement is true about the following molecule?  (1 point)The molecule is composed of four atoms.The molecule contains oxygen atoms.The molecule is water.The molecule represents an element. 2.   A(n) _____________ is made up of two or more different atoms that...

Science
A)Could you add marbles to a beaker filled with sand and get the same results? B)How does the Particle theory model explain that a substance can be solid while having spaces between its particles? C)Why does 50 ml of water and 5oml of sugar NOT produce 100 ml of a solution ...

Chemistry
How do I calculate moles from the given litres and mass of the substance (in grams)?

Chemistry
How do I calculate moles from the given litres and mass of the substance (in grams)?

Chemistry
Solutions of NiSO4(aq), Al2 (SO4)3 (aq), CoSO4 , and SnSO4 (aq) are in bottles labelled A, B, C, and D. a) Design an experiment to identify which ionicsulfate solution is in which bottle. Give a list of equipment and chemicals required. Describe a step-by-step procedure for ...

Chem
How do you determine the rate of reaction of a substance using stoichiometry and the average volume of the reaction on mixture?

AP Chemistry
A 2.8 gram sample of a gaseous substance occupies 12 L at 47 degrees C and 683 torr. What is the density of the gas under these conditions? Answer in units of g/L

Chemistry
1) Calculate the energy. in joules, of a photon of wavelength 1.250x 10^3 nm 2) If 3.011x 10^23 molecules have a mass of 20.04 grams, what is the molar mass of the substance? Is it 40.07g/mol? 3) 47.5g of Boron contains __________ atoms of B? Is it 2.65x10^24 4) What is the ...

chem
How do I calculate the rate of a reaction of a substance using the slope of the lines and stoichiometry of the reactions in moles/sec. I also know that the molarity of that substance.

Statistics
Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the data to construct a 90% ...

science
1.What two things happen to particles in a substance when the substance is heated? 2. What are the three most common states of matter on Earth? 3. Why does a liquid take the shape of whatever container it is in but does not expand to fill the container completely? 4. A certain...

General Chemistry
How do the vapour pressure of two substance at the same temperature but with different strengths of the inter-molecular forces compare. Give a molecular explanation of why this is so.

physics
7/8 part of a substance decays in 45 days what is its half life

Chemistry
5. On the basis of a solubility curve for KNO3 what type of substance would you expect KNO3 to be? Choices: solid liquid gas It is impossible to tell. I don't want the answer. All I want to know is, can you tell whether something is a liquid/solid/gas just by using a ...

Physics
An aluminum calorimetry cup [mc = 0.6 kg, cc = 0.22 kcal/(kgC)] is filled with water [mw = 2.4 kg, cw = 1 kcal/(kgC)]. It is at a temperature of 30C. A sample of an unknown substance with mass mm = 2.34 kg, originally at a temperature of 210C, is added. After a while, the ...

Physics
An aluminum calorimetry cup [mc = 0.6 kg, cc = 0.22 kcal/(kgC)] is filled with water [mw = 2.4 kg, cw = 1 kcal/(kgC)]. It is at a temperature of 30C. A sample of an unknown substance with mass mm = 2.34 kg, originally at a temperature of 210C, is added. After a while, the ...

help pls asap!!!!! check my answers!!! 4.) A certain object has a volume of 25.0 mL and a mass of 100g. What is the density of the object? a)0.250 g/mL b) 4.00/mL*** c)125 g/mL d) 2500 g/mL 5.)Which of the following is a chemical property of aluminum? a)The melting point of ...

science
plz any one these are some mcqs i am preparing for a test i m not sure with the answers of these mcqs this is not a homework not an online course exam so feel free to answer these thankx MCQS 01. Changes of equal magnitude are separated by some distance. If the changes are in ...

science
plz any one these are some mcqs i am preparing for a test i m not sure with the answers of these mcqs this is not a homework not an online course exam so feel free to answer these thankx MCQS 01. Changes of equal magnitude are separated by some distance. If the changes are in ...

Physics
plz any one these are some mcqs i am preparing for a test i m not sure with the answers of these mcqs this is not a homework not an online course exam so feel free to answer these thankx MCQS 01. Changes of equal magnitude are separated by some distance. If the changes are in ...

Science
plz any one these are some mcqs i am preparing for a test i m not sure with the answers of these mcqs this is not a homework not an online course exam so feel free to answer these thankx MCQS 01. Changes of equal magnitude are separated by some distance. If the changes are in ...

Science
1. The combination of sulfur dioxide, nitrogen oxide, and atmospheric moisture creates A. drinking water. B. smog. C. pesticides. D. acid rain. D? 2. Another name for unicellular organisms that dominated Earth up to the Precambrian time is A. eukaryotes. B. cyanobacteria. C. ...

science---1 question
help pls asap! 2) Which of the following is a pure substance? (1point) Chocolate milk Orange juice Seawater Hydrogen peroxide (H2O2) i first thought it was C (seawater) but is it D (H2O2)!??

chemistry
An unknown substance has a mass of 28.1 g. The temperature of the substance increases by 16.3 degrees Celsius when 176 J of heat is added to the substance. What is the most likely identity of the substance? The table lists the specific heat capacities of select substances.

Physics
An aluminum calorimetry cup [mc = 0.6 kg, cc = 0.22 kcal/(kgC)] is filled with water [mw = 2.4 kg, cw = 1 kcal/(kgC)]. It is at a temperature of 30C. A sample of an unknown substance with mass mm = 2.34 kg, originally at a temperature of 210C, is added. After a while, the ...

Chemistry
A certain substance has a heat of vaporization of 26.49 kJ/mol. At what Kelvin temperature will the vapor pressure be 5.00 times higher than it was at 285 K?

Penn Foster
1. In the 1500s, if you were searching for a sophisticated cosmopolitan urban center of learning in the Senegambia, you would have traveled to Timbuktu in the Kingdom of A. Kanem-Bornu. B. Benin. C. Songhai. (my choice) D. Mali. 2. Historians divide the Thirty Years' War into ...

AP Chemistry
The ionic substance T3U2 ionizes to form T2+ and U3− ions. The solubility of T3U2 is 4.07×10−20 mol/L. What is the value of the solubility-product constant?

Chemistry
ONe day, you were walking along the road with your friend and saw a piece of solid that you've never seen before. You were curious about the identity of the substance so you tried to give it to the Department of Science. You found out from them that it is a new found element ...

Science
No further energy can be removed from a substance when it is at ____ ____ Please help!

Check my Science questions?
1. Why is it rare for the soft parts of an organism to become a fossil? The soft parts take a long time to decay. The soft parts can be eaten by other animals. The soft parts cannot be buried in sediment. The soft parts form petrified fossils. 2. Which of the following terms ...

Science help,Anyone?
1. Why is it rare for the soft parts of an organism to become a fossil? The soft parts take a long time to decay. The soft parts can be eaten by other animals. The soft parts cannot be buried in sediment. The soft parts form petrified fossils. 2. Which of the following terms ...

1. Why is it rare for the soft parts of an organism to become a fossil? The soft parts take a long time to decay. The soft parts can be eaten by other animals. The soft parts cannot be buried in sediment. The soft parts form petrified fossils. 2. Which of the following terms ...

Science
Ions are electrically charged particles that are formed when certain compounds are dissolved in water. These solutions will conduct electricity. The Swedish scientist Svante Arrhenius coined the term ion (which means wanderer) to explain why solutions of electrolytes will ...

Pam
A 56.59 g sample of a substance is initially at 20.5 °C. After absorbing 1267 J of heat, the temperature of the substance is 116.5 °C. What is the specific heat (c) of the substance?

Chemistry Q1,3,5
1) What would be the preferred heating device (s) in each of the following situations? a) reflux a solvent with a 56 degree Celsius boiling point b) reflux a solvent with a 110 degree Celsius boiling point c) distillation of a substance that boils at 220 degree Celsius 3) What...

Science
Match these with the key terms (1) A form of energy that is always transferred from a warmer substance to a cooler one. (2) device that converts hear to a small amount of electric energy often used in temperature sensors. (3) A Push button barbecue lighter produces a small ...

Health (Ms. Sue)
1. What are two ways that society could deal with future concerns about genetic information? A: ? 2. Identify how keeping person health records can help a person cope with hereditary diseases. A: Keeping personal health records can help a person cope with hereditary diseases ...

Physical Chemistry
A pharmaceutical preparation of pH 6.2 is preserved with substance A (pKa 8.5). If the preservative effect is due to the undissociated molecule determine the per cent of active preservative present in the preparation. Thanks! :)

Math Expoents
One microgram is equal to 1x10^-6 gram. If the mass of a substance is 8x10^9 micrograms, what is its mass in grams? a) 1.25x10^-15 b) 1.25x10^-3 c) 8x10^3 d) 8x10^15

college algebra
Use a calculator to help solve the problem. An isotope of lead, 201Pb, has a half-life of 8.4 hours. How many hours ago was there 40% more of the substance? (Round your answer to one decimal place.) ____hr

Advanced Chem- Intermolecular Forces of Attraction
Answer/ explain the following in terms of intermolecular forces and properties of the substances referred to in each situation. 1. Why is it that if a glass is slightly filled above the brim with water, the liquid does not overflow? 2.Induced dipole forces or London force of ...

college algebra
An isotope of lead, 201Pb, has a half-life of 8.4 hours. How many hours ago was there 40% more of the substance? (Round your answer to one decimal place.) ____hr

Health (Ms. Sue)
1. Explain the relationship between the following key terms. a. physical dependence and withdrawal b. drug and medicine c. drug tolerance and addiction d. over-the-counter medicine and prescription e. active ingredient and drug interaction f. alcohol abuse and alcoholism g. ...

AP Chemistry
How do you determine the heat of solution for a substance? how can we report this answer in both kJ/g and kJ/mol? thank you!!!

college essay
can someone edit my college essay? I was told by an admissions counselor to write a supplement describing my low cumulative GPA. It is a rough first draft, and probolaly needs to be heavily edited I am my truest and purest self, a mere child embarking on the beginning of the ...

Health
3. All drugs are not medicines because not all drugs are used to cure, prevent, of treat illness or discomfort. In fact, some drugs possess mind-altering effects that have no medical purpose such as drugs of abuse, which alters the manner in which the brain functions in means ...

chemistry
given 10.8 grams of substance y,if the substance absorbs 231 kilojoules of energy and the specfic heat of substance is 6.55 J/g*0C what is the heat change

biology
Substance X is converted to substance Y in a chemical reaction. What role would a catalyst play in this scenario? A. It would increase the solubility of substance X into the solvent needed to speed up the reaction. B. It would speed up the reaction by becoming part of the ...

Health (Ms. Sue)
Compare the term drug with the term medicine. A: The term drug and the term medicine both describe types of drugs. However, these types of drugs are very different. For example, the term drug is any substance that causes a change in a person’s physical or psychological state...

Chemistry
For the following reaction, identify the substance oxidized, reduced and the oxidizing and reducing agents. 2SO2 + O2 ----> 2SO3

AP Chemistry
Calculate ∆G0 for the following reaction. 4XY + 3Z2−→2Z3X2+ 2Y2 Substance ∆H0f S0kJ/mol J/mol·K XY 205.0 75.0 Y2 −82.0 37.0 Z2 −25.0 78.0 Z3X2 −245.0 137.0 Answer in units of kJ/mol

Organic Chemistry
I want to confirm some things on solubility and boiling points(they might be right or wrong): - If a substance is soluble in water then it also has a high boiling point - If a substance has a high intermolecular force then it also has a high boiling point - Shorter ...

Science
Please help !!! A student wanted to determine the density of an object made of an unknown substance. She found the mass of the object was 335g. Then she did water displacement to determine the objects volume. The initial volume of the water was 50.0 mL. With the object ...

chemistry
A solid sample is 81.0 g sodium per 1,000,000. g substance, and contains 1.92 × 10 ^21 sodium atoms, calculate the mass (g) of the sample.

Science
What is a substance that cannot be separated into simpler substances by physical or mechanical methods such as filtering, boiling, or sifting?

science
I am still new to physics, so I'm having a rough time. When a 1kg metal pan containing 1kg of cold water is removed from a refrigerator onto a table which absorbs more heat from the room, the pan or the water? I thought it was the water, because I thought I read that water has...

Chemistry
what's the density of a cube of an unknown substance if mass is 45.2g and the side of a cube is 3.2cm?

Biology
What happens when a substance dissolves in the watery solution outside of a cell and equilibrium is disrupted. a. Water from the cell will move into the solution b. water from the solution will move into the cell c. the pores in the cell membrane will become clogged with the ...

Science
Suppose that 9 grams of a certain substance lost 17.5 calories of heat when the temperature decreased from 70 degrees Celsius to 62 degrees Celsius. What is the Cp

Calculus
Romat 421 (a fictitious substance) decays by about 1.5% every day. How much of a 80 pound sample remains after 5days?

ap chemistry
A sample of 1.67 grams of Z is dissolved into 500 grams of water which is in a Styrofoam coffee cup. The temperature is monitored and is found to rise from 25.594◦C to 26.041◦C. What is Hsolution for substance Z? Assume no heat is lost/gained by the cup itself. ...

science
A substance that has a mass of 20g and volume of 10cm3. How much mass does one cm3 of this substance have? A substance with a mass of 125g and a volume of 25cm3. How much mass does one cm3 of this substance have? Please tell me how to do this.

cor biology
Substance X has a molar extinction coefficient (E) of 4725 l.mol-1. How many moles of X are needed to produce an absorbance of 1.0 in a 1 ml cuvette?

Chemistry
Is boron trichloride a Giant covalent or Simple molecular substance?

college essay
can someone help me edit this My Song My existence thus far has been a musical performance. The world is my stage, the platform upon which I express myself creatively. My life is the reputable melody that I play on my guitar, and the notes are my memories and life experiences...

Chemistry
1)Which substance ( Ar or F2 ) has the higher boiling point? Select the two most important reasons below to justify your choice should have the higher boiling point *Both substances are nonpolar but the higher boiling includes hydrogen bonding *Both substances are nonpolar but...

Chemistry
Which substance ( HI or Xe ) has the higher boiling point? Its HI but chose one of the most appropriate reason. 1. Both substances are nonpolar but the higher boiling includes hydrogen bonding 2. Both substances are nonpolar but the higher boiling is more polarizable 3. The ...