# science

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

1. 👍
2. 👎
3. 👁
1. 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

1. 👍
2. 👎

## Similar Questions

1. ### Educational Technology

1. Which of the following choices is a strategy that could help with time management? A. Spending most of the day on leisure activities. B. Doing homework in every spare moment. C. Cutting back on sleep. D. Creating a list of

2. ### ELA

which sentence is in the imperative voice 1 how much homework do you have 2 is it important to do homework 3 do your homework as soon as you get home 4 homework should be done thoroughly i think its the 3rd one am i right?

3. ### English

Identify the correct sentence. A. I did my homework when the doorbell was ringing. B. I do my homework when the doorbell is ringing. C. I was doing my homework when the doorbell rang. D. I was doing my homework when the doorbell

4. ### ENGLISH

Identify the correctly punctuated sentence. I marked the one I think it is. • Doing my homework, making my bed, and practicing guitar are on my to-do list for the day. • Doing my homework, is the first thing I should do. •

1. ### Math

Ivan finished 4/5 of his math homework problems and all 3 questions for his science homework before dinner . If he finished a total of 43 problems before dinner , what is the total number of math homework problems he was assigned?

2. ### Math

On Tuesday, Leslie spent 47 minutes on math homework, 39 minutes on science homework, 52 minutes on English homework, and 44 minutes on history homework. How much time did Leslie spend doing her homework on Tuesday?

3. ### Math

There is a 60% that your math teacher will give a pop quiz tonight and, due to the fact that you have a soccer game, there is an 85% chance you will not be able to do your math homework. You decide that you will do the homework if

4. ### Fractions

Lee finishes 2/3 of her homework in 3/4 hours. how long will it take her to finish all of her homework?

1. ### English

Identify the sentence that varies from formal standard English. A) I did not finish my social studies homework because I had a ton of math homework. B) I did not complete my social studies homework because I was busy with my math

2. ### Micro- Econ

You have an hour between your economics and math classes. What is the opportunity cost of that time if you use it to complete your math homework instead of your economics homework? the economics homework you could have completed

3. ### TO JOEY AND OTHERS

Please remember these things: 1. This is a homework help website; please put your subject (math, science, English, or ??) in the subject line to make it faster for each teacher to find those questions in his/her areas. An even

4. ### TO ALL STUDENTS

Please remember these things: 1. This is a homework help website; please put your subject (math, science, English, or ??) in the subject line to make it faster for each teacher to find those questions in his/her areas. An even