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

1. B   2. B   3. C   4. A     5. A

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.

chemistry sucks a**

explanation:

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.