I need some help with my science homework. Well it is not really my homework it is my study guide but the actual test is the same as the study guide almost. They just switch around the words and stuff around to mess with your mind. These were just the only 7 problems I need help with out of all 100 problems in the study guide.
3.
The rows in the periodic table indicate the number of _______________ or energy levels
A) points
B) nucleus
C) particles
D) electron orbitals
4.
Columns indicate the number of _________________ in the outer shell.
A) quarks
B) neutrons
C) protons
D) electrons
25.
Calculate the number of moles in 34 grams of copper (Cu).
A) 0.54 moles Cu
B) 63.5 moles Cu
C) 34 moles Cu
D) 54 moles Cu
26.
Convert 22 grams of copper to atoms of copper (Cu). Hint: Remember Avogadro
A) 2.09 X 1023
B) 3.5 X 1023
C) 1.09 X 1023
D) 6.5 X 1023
27.
Calculate the number of g that are in 39.0 mol of CaO.
A) 2190 g or 2.19 x 103 g
B) 56g
C) 16 g or 1.6 x 103 g
D) 5190 g or 5.19 x 103 g
28.
Calculate the number of mol that are in 0.608 g of SiO2.
A) 0.0535 mol or 5.35 x 10-2 mol
B) 60.804 mol
C) 0.0608 mol or 6.08 x 10-2 mol
D) 0.0101 mol or 1.01 x 10-2 mol
3)D
4)D
25)A
When we look in the periodic table of elements, we find that copper has an atomic weight of 63,5 g/mol
=> 34g/(63,5g/mol) = 0,54 mol
26)A
Using the previous exercise as an example, we are able to calculate the number of mol in 22 grams of copper
=> 22g/(63.5g/mol) = 0.346 mol
We know that Avogrado's number indicates the number of particles (i.e. atoms or molecules) per mol and this number equals 6.023*10^23.
So 0.346 mol*6.023*10^23particles/mol = 2.09*10^23 particles
27)A
We find in the periodic table that the atomic weights of Calcium and Oxygen are resp. 40 and 16 g/mol. So the molecular weight of CaO equals 40+16 g/mol = 56 g/mol
=> 39.0 mol * 56 g/mol = 2190 g
28) D
We find in the periodic table that the atomic weights of Silicon and Oxygen are resp. 28 and 16 g/mol. So the molecular weight of SiO2 equals 28+(2*16) g/mol = 60 g/mol
=> 0.608g/(60g/mol)= 0.0101 mol
Sure, I can help you with your science questions. Let's go through each question one by one.
3. The rows in the periodic table indicate the number of _______________ or energy levels.
To answer this question, you can look at the periodic table and count the number of rows. Each row represents a different energy level for the elements. The correct answer is D) electron orbitals.
4. Columns indicate the number of _________________ in the outer shell.
To answer this question, you need to understand the structure of an atom. The outer shell refers to the outermost energy level of an atom, which determines its chemical properties. Each column in the periodic table represents the number of electrons in the outer shell. The correct answer is D) electrons.
25. Calculate the number of moles in 34 grams of copper (Cu).
To calculate the number of moles, you need to use the formula: moles = mass / molar mass. The molar mass of copper (Cu) is 63.5 g/mol. Divide the mass (34 grams) by the molar mass to find the answer. The correct answer is A) 0.54 moles Cu.
26. Convert 22 grams of copper to atoms of copper (Cu).
To convert grams to atoms, you need to use Avogadro's number, which is 6.022 x 10^23 atoms/mole. First, calculate the number of moles of copper by dividing the mass (22 grams) by the molar mass (63.5 g/mol). Then, multiply the number of moles by Avogadro's number to get the number of atoms. The correct answer is A) 2.09 x 10^23.
27. Calculate the number of g that are in 39.0 mol of CaO.
To calculate the number of grams, you need to use the formula: grams = moles x molar mass. The molar mass of CaO is 56 g/mol. Multiply the number of moles (39.0 mol) by the molar mass to find the answer. The correct answer is A) 2190 g or 2.19 x 10^3 g.
28. Calculate the number of mol that are in 0.608 g of SiO2.
To calculate the number of moles, you need to use the formula: moles = mass / molar mass. The molar mass of SiO2 is 60.08 g/mol. Divide the mass (0.608 grams) by the molar mass to find the answer. The correct answer is C) 0.0608 mol or 6.08 x 10^-2 mol.
I hope this helps you with your science homework. If you have any more questions, feel free to ask!