Revision lesson
Francine Taylor-Campbell, Contributor

We will assess how well you have understood the concepts discussed earlier in the year through multiple-choice items. Special notes or comments will be used to highlight important points or common mistakes students can make.

Choose the correct answer to the following questions.

1. Which statement about the behaviour of the particles in a gas is not correct?

A. They spread throughout the vessel in which they are contained.

B. They are able to move at high speeds.

C. They are arranged in regular patterns.

D. There are large spaces between the particles.

E. Their collisions with the walls of the vessel cause pressure.

2. An atom of element X has the symbol ⁷₃ X. Which statement about X is correct?

A. It is in Group III of the Periodic Table.

B. It is in Group VII of the Periodic Table.

C. In one atom, the number of protons + the number of electrons is 6.

D. In one atom, the number of protons + the number of neutrons is 10.

E. The electron arrangement is 2:5.

3. Two particles X and Y have the following atomic particles:

X - 6 protons and 6 neutrons

Y - 6 protons and 8 neutrons

Which term describes X and Y?

A. allotropes

B. ions

C. isomers

D. isotopes

4. An inflated balloon will shrink if placed into a refrigerator. This is because the lower temperature causes the gas particles in the balloon to move

A. faster and become closer together

B. faster and become further apart

C. slower and become closer together

D. slower and become further apart

5. The atoms 3115 P and 3216 S have the same

A. nucleon number

B. number of electrons

C. number of neutrons

D. number of protons

ANSWERS AND COMMENTS

1. C. Gases are not arranged in regular patterns, instead they fill the space of any container in which they are placed and have no shape.

2. C. In element X, the number of protons (atomic number) is the bottom number which is 3 and this is also equal to the number of electrons in an uncharged atom. Therefore, the protons + electrons = 3 + 3 = 6. Element X is not in Group 3 or 7 of the Periodic Table as its electronic configuration 2:1 (3 electrons) puts it in Group I (1 electron in the outer shell).

3. D. X and Y have the same number of protons (atomic number), but different number of neutrons, hence they are isotopes.

4. C. An inflated balloon contains gas particles which have spread out. Upon freezing, the energy of the particles and hence their movement is reduced causing them to slow down and come closer together. Eventually they will freeze and become a solid, having close arrangement of particles.

5. C. The number of neutrons is found by subtracting the number of protons from the mass number. N = M - P. If this is done for P, then 31 - 15 = 16 and for S 32 - 16 = 16. The atoms P and S contain the same number of neutrons = 16.

Christopher Barnes, The Gleaner's deputy managing director, has the attention of students of Holy Childhood High School in St Andrew, on May 4. - Ricardo Makyn/Staff Photographer

Francine Taylor-Campbell is an independent contributor.