The Law of Conservation of Mass – during a ________ reaction, the mass (65) _______ the reaction must _______ the mass after the reaction. We show this by (66) writing and balancing a chemical _______. When we write a chemical equation, (67) we use the chemical _______ for the elements and _______ to indicate how (68) many atoms of each element are present in the reaction.
The Law of Conservation of Mass – during a chemical reaction, the mass (65) 'before' the reaction must (66) 'equal' the mass after the reaction. We show this by (66) writing and balancing a chemical equation. When we write a chemical equation, (67) we use the chemical symbols for the elements and (68) subscripts to indicate how many atoms of each element are present in the reaction.
______are the starting ______that react with each other to form new substances. (72) Products are the ______results of the ______reaction. Balanced equations have (73) ______number of atoms on both ______of the equation. This shows matter is (74) neither ______nor destroyed.
Reactants are the starting materials that react with each other to form new substances. (72) Products are the end results of the chemical reaction. Balanced equations have (73) an equal number of atoms on both sides of the equation. This shows matter is (74) neither created nor destroyed.
The ______is the number in ______of the element or ______. It indicates how (76) many of that ______are part of the reaction. If ______number is written, then the (line 77) 1 is a given (we wouldn’t write the ______if it was not there).
(78) The subscript is ______and slightly below the ______. It indicates how many (79) ______of that element are in the molecule. If no ______is written, then the 1 is a (80) given.
The subscript (75) is the number in lower case to the right of the element or molecule. It indicates how (76) many of that element or molecule are part of the reaction. If no (77) number is written, then the 1 is a given (we wouldn’t write the (line 78) subscript if it was not there).
The subscript (79) is smaller and slightly below the line. It indicates how many (80) atoms of that element are in the molecule. If no (81) subscript is written, then the 1 is a (82) given.
Balance these ______equations, making sure you have the same ______of each (82) ______on the left and ______of the arrow.
Balance these chemical equations, making sure you have the same number of each (82) element on the left and right of the arrow.
_______HgO ---> _______Hg + _______O2
2 HgO ---> 2 Hg + O2
___C3H8 + _______O2 ---> _____3CO2 + _______2H2O
C3H8 + 5 O2 ---> 3 CO2 + 4 H2O
In a physical ______, molecules remain the same and ______the same properties (84) as they change states.
(85) ______change: A + B 🡪 AB substances ______but keep the same properties (86) Sand + water + rocks 🡪 ______of sand, water, and rocks
(87) Chemical ______A + B 🡪 C new ______with different properties (88) Eggs + flour + sugar + butter 🡪 cake
(89) Characteristics of chemical reactions include:
• (90) ______ change when reactants come into contact with each other • (91) Production of _____not caused by boiling a liquid
In a physical (83) change, molecules remain the same and retain the same properties (84) as they change states.
(85) Physical change: A + B 🡪 AB substances combine but keep the same properties (86) Sand + water + rocks 🡪 mixture of sand, water, and rocks
(87) Chemical change A + B 🡪 C new substances with different properties (88) Eggs + flour + sugar + butter 🡪 cake
(89) Characteristics of chemical reactions include:
• (90) Color change when reactants come into contact with each other
• (91) Production of gas not caused by boiling a liquid
Precipitate formation – when a solid is ______ (precipitate) in a reaction • (93) Changes in ______can indicate a ______in energy
Precipitate formation – when a solid is formed (precipitate) in a reaction • (93) Changes in temperature can indicate a change in energy.
Physical change
Size and ______
Physical change can also involve changes in size and shape.
Example
Piece of ______chopped
Example: A piece of wood being chopped into smaller pieces.
Change in state
Ice ______
Example: Ice melting into liquid water.
Composition is the same,
______of molecules is different
Example: Water vapor condensing into liquid water.
Composition is the same, ______of molecules is differen
Example: Water molecules evaporating into water vapor.
Mixtures
Mixing dried ______
Example: Mixing dried herbs together to create a spice blend.
______
Painting a fence
Example: Painting a fence involves applying a layer of paint onto the surface of the fence.
painting fence is hat type of change
Painting a fence is a physical change. It involves applying a layer of paint onto the surface of the fence, but the composition of the fence itself does not change.
______in the banana peel
______resulting in a different colo
Example: Enzymes in the banana peel breaking down the pigments, resulting in a different color.
The Law of _conservation__________of Matter states that _energy_____is not created or destroyed, (95) only ______. Both the ______of Conservation of Matter and the Law of (96) Conservation of Mass state that ______are not created or ______. Atoms make (97) up the mass of a substance. According to the ______of Conservation of ______, (98) the mass before a chemical ______is the same as the mass after a chemical (99) reaction.
The Law of Conservation of Matter states that energy is not created or destroyed, (95) only transferred or transformed. Both the Law of Conservation of Matter and the Law of (96) Conservation of Mass state that matter and mass are not created or (96) destroyed. Atoms make up the mass of a substance. According to the (97) Law of Conservation of Mass, the mass before a chemical (98) reaction is the same as the mass after a chemical (99) reaction.
In which chemical equation is the number of atoms in the reactants the same as the number of atoms in the products?(1 point)
Responses
CH4 + O2 → CO2 + 2H2O
CH 4 + O 2 → CO 2 + 2H 2 O
Zn + 2HCl → H2 + ZnCl2
Zn + 2HCl → H 2 + ZnCl 2
CO2 + H2O → CH2OH + O2
CO 2 + H 2 O → CH 2 OH + O 2
Li2CO3 → LiO + CO2
The chemical equation in which the number of atoms in the reactants is the same as the number of atoms in the products is:
Zn + 2HCl → H2 + ZnCl2
Which statement is true regarding a chemical reaction?(1 point)
Responses
The total number of atoms changes, so mass is conserved in the reaction.
The total number of atoms changes, so mass is conserved in the reaction.
Even if the total number of atoms does not change, mass may not be conserved in the reaction.
Even if the total number of atoms does not change, mass may not be conserved in the reaction.
Even if the total number of atoms changes, mass may not be conserved in the reaction.
Even if the total number of atoms changes, mass may not be conserved in the reaction.
The total number of atoms does not change, so mass is conserved in the reaction.
The total number of atoms does not change, so mass is conserved in the reaction.
The statement that is true regarding a chemical reaction is:
The total number of atoms does not change, so mass is conserved in the reaction.
FeCl3 + 3H2O → Fe(OH)3 + 3HCl
Element Mass of an Atom (amu)
Fe 56
Cl 35
H 1
O 16
Iron chloride and water react according to the equation shown. The table shows the atomic masses of the elements involved in the reaction. What is the total mass of the reactants?
(1 point)
Responses
161 amu
161 amu
215 amu
215 amu
108 amu
108 amu
179 amu
179 amu
Skip to navigation
To calculate the total mass of the reactants, we need to find the individual masses of each atom present in the reactants and multiply them by their respective coefficients in the balanced equation:
FeCl3:
1 iron (Fe) atom → 1 * 56 amu = 56 amu
3 chlorine (Cl) atoms → 3 * 35 amu = 105 amu
H2O:
6 hydrogen (H) atoms (3 from each water molecule) → 6 * 1 amu = 6 amu
3 oxygen (O) atoms (1 from each water molecule) → 3 * 16 amu = 48 amu
Total mass of the reactants = Mass of FeCl3 + Mass of H2O
= 56 amu + 105 amu + 6 amu + 48 amu
= 215 amu
Therefore, the total mass of the reactants is 215 amu.
In a chemical reaction, two molecules with a total mass of 76 amu react to form a single molecule. What is the mass of the molecule that is formed?(1 point)
Responses
228 amu
228 amu
76 amu
76 amu
152 amu
152 amu
38 amu
The mass of the molecule that is formed in a chemical reaction cannot be determined solely based on the given information. The mass of the resulting molecule depends on the specific elements and their composition in the reaction.
) The Response areais the number in Response areaof the element or compound.
I apologize for the confusion, but I'm unable to determine the context of your statement. Could you please provide more information or clarify your question?
The ____is the number in ____ of the element or compound
The subscript is the number in lower case to the right of the element or compound.
is coefficient subscript?
No, the coefficient is not the subscript. The coefficient is the number in front of a compound or element that indicates the number of molecules or atoms present in the reaction. The subscript, on the other hand, is the number written in a slightly lower position and to the right of an element symbol, indicating the number of atoms of that element within a molecule.
If the total mass of the product, mercuric oxide, HgO, is 433.2 grams, what is the total mass of the Mercury and Oxygen on the reactants side of the equation?
Type your answer in the below box.
To determine the total mass of mercury and oxygen on the reactants side of the equation, we need to know the balanced chemical equation for the reaction. Without the specific equation, it is not possible to accurately calculate the masses of the reactants.
2Hg + O2---> 2HgO
In the balanced chemical equation 2Hg + O2 -> 2HgO, we can determine the total mass of mercury (Hg) and oxygen (O2) on the reactants side.
From the equation, we see that the coefficient of Hg is 2 and the coefficient of O2 is 1.
To calculate the mass, we need to know the molar mass of each element. The molar mass of mercury (Hg) is approximately 200.59 g/mol, and the molar mass of oxygen (O) is approximately 16.00 g/mol.
Total mass of mercury (Hg) on the reactants side: 2 * 200.59 g/mol = 401.18 g
Total mass of oxygen (O2) on the reactants side: 1 * 32.00 g/mol = 32.00 g
Therefore, the total mass of mercury and oxygen on the reactants side of the equation is approximately 401.18 g (for Hg) + 32.00 g (for O2) = 433.18 g.
True or False: During adolescence, your self-esteem may influence you to choose other friends or reject the friends you’ve had for years.
(1 point)
Responses
true
true
false
True.
You decide you are going to make more responsible health decisions. Which of the following risk factors can you control?
(1 point)
Responses
Unintentional accidents are the leading cause of death for teens.
Unintentional accidents are the leading cause of death for teens.
Your friends have recently started smoking.
Your friends have recently started smoking.
There is a history of heart disease in your family.
There is a history of heart disease in your family.
There is a higher incidence of high blood pressure in your ethnic group.
You can control the risk factor of your friends recently starting smoking.
You discover a red bump on your leg that itches. You decide to research the symptoms to determine if you need to go to the emergency room. While researching, you discover contradictory information. What is the best next step?
(1 point)
Responses
Assume the bump is life threatening and immediately go to the emergency room.
Assume the bump is life threatening and immediately go to the emergency room.
Implement the solution from the first source.
Implement the solution from the first source.
Decide there is no issue and do nothing.
Decide there is no issue and do nothing.
Continue searching for reliable resources on the topic.
The best next step would be to continue searching for reliable resources on the topic. It is important to gather as much information as possible from trustworthy sources before making any decisions regarding your health.
Lifestyle choices and health awareness affect your position on the health
(1 point)
Responses
continuum.
continuum.
wellness scale.
wellness scale.
risk factor chart.
risk factor chart.
rating.
continuum
Which of the following physical changes are experienced by teen males?
(1 point)
Responses
widening of the hips
widening of the hips
development of the breasts
development of the breasts
broadening of the shoulders
broadening of the shoulders
narrowing of the waist
The physical change experienced by teen males is broadening of the shoulders.
The start of puberty varies greatly and can begin as early as ___ years old and as late as ___ years old.
(1 point)
Responses
5, 10
5, 10
5, 20
5, 20
8, 16
8, 16
10, 30
The start of puberty varies greatly and can begin as early as 8 years old and as late as 16 years old.
According to the CDC guidelines, children and adolescents should get at least ____ minutes of physical activity every day.
(1 point)
Responses
15
15
30
30
45
45
60
According to the CDC guidelines, children and adolescents should get at least 60 minutes of physical activity every day.
Why are teenagers more likely to make rash decisions and not be able to control impulses than adults?
(1 point)
Responses
All of their organs are growing.
All of their organs are growing.
Their hormones slow down their brain.
Their hormones slow down their brain.
Their prefrontal cortex is being rewired.
Their prefrontal cortex is being rewired.
Their amygdala has not been developed yet.
Their prefrontal cortex is being rewired.
Which of the following is a common barrier to being more active?
(1 point)
Responses
having friends who like to be active
having friends who like to be active
not knowing who to ask about how to be more active
not knowing who to ask about how to be more active
having a regular doctor
having a regular doctor
not having access to the Internet
Not knowing who to ask about how to be more active is a common barrier to being more active.
The height of an equilateral triangle equals 3√2 times the side length. Using 74 for the square root of 3, what is the approximate height in meters of an equilateral triangle with a side length of 8 meters?(1 point)
The height of an equilateral triangle is given by the formula:
height = side length * √3 / 2
Given that the side length of the triangle is 8 meters and that 74 is approximately the square root of 3, we can substitute the values into the formula:
height = 8 * 74 / 2 ≈ 296 / 2 ≈ 148
Therefore, the approximate height of the equilateral triangle is 148 meters.
The height of an equilateral triangle equals 3√2 times the side length. Using 7/4 for the square root of 3, what is the approximate height in meters of an equilateral triangle with a side length of 8 meters?(1 point)
The height of an equilateral triangle is given by the formula:
height = side length * √3 / 2
Given that the side length of the triangle is 8 meters and that 7/4 is the approximate value of the square root of 3, we can substitute the values into the formula:
height = 8 * (7/4) / 2 = 56/2 =