Chapter 1 - Summary Questions

Question 1

a) Name the elements in this list: Ca, CH4, H2, HCl, MgO, Ne, O2, SO2.
b) What general name is given to the other substances in the list?

Answer 1

a) Calcium, Hydrogen, Neon, Oxygen

b) compounds

Question 2

The unbalanced equation for a reaction is:

a) Balance the equation
b) Write the word equation for the reaction.

Answer 2

a) H2 + Cl2 —-> 2HCl

b) Hydrogen + chlorine —–> Hydrogen chloride

Question 3

Name a process you could use to separate ethanol and water.

Answer 3

Fractional distillation

Question 4

What determines the order of the elements in the periodic table?

Answer 4

In order of atomic (proton) number.

Question 5

a) Name the three types of sub-atomic particle

b) State the relative mass and relative charge of each sub-atomic particle.

Answer 5

a) proton; neutron; electron
b) proton - relative mass - 1, relative charge - +1
Neutron - relative mass - 1, relative charge - 0
Electron - relative mass - very small, relative charge - -1.

Question 6

Describe how you could produce salt crystals from salt solution.

Answer 6

Heat the sodium chloride solution in an evaporating dish on a water bath; stop heating when small crystals first appear around the edge of the solution; the rest of the water is then left to evaporate to obtain sodium chloride crystals.

Question 7

Why are magnesium and calcium in group 2 of the periodic table?

Answer 7

Both have two electrons in their highest energy level (outer shell).

Question 8

Magnesium metal (Mg) reacts with dilute hydrochloric acid (HCl) to form a solution of magnesium chloride (MgCl2) and hydrogen gas (H2). 
Write a balanced symbol equation, including state symbols, for this reaction.

Answer 8

Mg(s) + 2HCl(aq) —> MgCl2(aq) + H2(g)

Question 9

The atomic radius of a silver atom is 1.44 x 10-¹⁰m. Give the atomic radius of silver in nanometers.

Answer 9

0.144nm

Question 10

There are three types of hydrogen atom: 1/1 H, 2/1 H, 3/1 H.

a) What name is used for these three types of atom?
b) Describe how the three types of atom are different.

Answer 10

a) Isotopes

b) have a different number of neutrons or 1/1 H has no neutrons, 2/1 H has one neutron and 3/1 H has two neutrons.

Question 11

Describe the differences between JJ. Thomson’s ‘plum pudding’ model of the atom and Rutherford’s nuclear model of the atom.

Answer 11

Thomson - tiny negatively charged electrons embedded in a cloud of positive charge.
Rutherford - the positive charge is concentrated in a nucleus in the centre of the atom; the electrons are orbiting the nucleus.