Question

1. Which atom contains exactly 16 neutrons?

A S-33
B P-31
C O-16
D Cl – 35
2. In a mass spectrometer
A Particles with the most mass are deflected the most
B Particles with the least mass are deflected the most
C Particles with the least mass are deflected the least
D All particles are deflected the same
3. Calculate the mass, in grams, of 3.00 moles of carbon.
A 3.00 grams C
B 18.0 grams C
C 36.0 grams C
D 54.0 grams C
4. Calculate the number of moles of aluminum in 65 grams of aluminum?
A 2.4 moles Al
B 5.0 moles Al
C 850 moles Al
D 1800 moles Al
5. Calculate the number of atoms of sodium in a 4.5-gram sample.
A 1.2 x 1023 atoms Na
B 2.5 x 1023 atoms Na
C 1.7 x 10-22 atoms Na
D 3.1 x 1024 atoms Na

Answer 1

1. B 2. B 3. C 4. A 5. A

Step-by-step explanation:

1 Which atom contains exactly 16 neutrons?

Neutrons = Mass Number - Proton

A -33;

Neutrons = 33 - 16 = 17

B P-31

Neutrons = 31 - 15 = 16 Correct option

C O-16

Neutrons = 16 - 8 = 8

D Cl – 35

Neutrons = 35 - 17 = 18

2. In a mass spectrometer, the heaviest particles are least deflected and that with the least mass are deflected the most. The correct option is B.

3. 1 mol of C = 12 grams;

3 mol = x

x = 3 * 12 = 36 grams Correct option is C

4. 1 mol = 27g of Al;

x mol = 65g

x = 65 / 27 = 2.4 moles. Correct option is A.

5. There are 6.022 x 10^23 atoms in 23 grams of sodium;

x atoms in 4.5g

x = 6.022 x 10^23 * 4.5 / 23 = 1.2 x 10^23 atoms Correct option is option A.