Science 9 Review: Ch 2.1
1.
If a chemical symbol has two letters, are both letters capitalized? (p43)
No, just the first letter is capitalized, like Fe or Ag
2.
The element iron has the symbol Fe rather than I or Ir. Explain why. (p44)
Iron was known by the Romans as ferrum (Latin) so the symbol is Fe.
3.
List 3 properties (chemical or physical) of sodium that are different from the properties of iron. (p45)
Sodium has a lower density than water (floats in water). Sodium reacts strongly with water releasing hydrogen gas. Sodium produces a very strong base, sodium hydroxide
(an alkali), when it reacts with water.
4.
What are some of the properties of iron that make it a good material for construction? (p45)
Iron is strong, it can be drawn into wires (ductile), it can be formed into various shapes
(malleable).
5.
What is mercury’s unique property? (p46)
Mercury is a liquid metal at room temperature.
6.
List 2 ways that chlorine is beneficial to humans. (p46)
Chlorine kills bacteria and it combines with sodium to form table salt.
7.
What are three useful properties of silver? (p47)
Silver can be moulded, stretched and is malleable. It is used for making teeth fillings. It is the best conductor of electricity. It is used to make high quality flutes. It is a good reflector of light.
8.
What is an element? (p 23)
An element is a pure substance made up of only one kind of atom. It can not be broken down chemically into anything simpler.
9.
About how many elements are there? (p 43)
There are more than 115 elements
10.
Why are chemical symbols for elements used? (p 43)
Chemical symbols use a maximum of two letters so it is much easier to refer to elements this way.
11.
Give the name and symbol for the element based on each of the following ancient meanings in table 2.1 (p44): a.
Goblin
Cobalt Co b.
Smelly
Bromine Br

Science 9 Review: Ch 2.1 c.
Violet
Iodine I d.
Emerald
Beryllium Be e.
Flowing
Fluorine F f.
New
Neon Ne g.
Pale green
Chlorine Cl h.
Liquid silver
Mercury Hg i.
Red
Rubidium Rb j.
Bluish-grey
Cesium Cs k.
Bringer of light
Phosphorus P
12.
Which is the lightest element? (p45)
Hydrogen H
13.
Which element conducts electricity best: gold or silver? (p47)
Silver Ag
14.
What elements are used to make steel? (google composition of steel)
Iron (Fe) and carbon (C)
15.
What percentage of our atmosphere is composed of oxygen? (p45)
21% of our atmosphere is oxygen
16.
What is the source of the oxygen in our atmosphere? (p45)
Plants have produced all the oxygen in our atmosphere.
17.
Explain why sodium would not be a good material for drinking glasses. (p46)
Sodium reacts violently with water, exploding.

Science 9 Review: Ch 2.1
18.
Why is the element chlorine used in swimming pools? (p46)
Chlorine kills bacteria
19.
Which element makes up over 90% of the atoms in the universe? (p45)
Hydrogen makes up 90% of the universe
20.
Which element does silicon combine with to make quartz? (p47)
Silicon reacts with oxygen to form quartz
21.
Compare the reaction of sodium with water to iron with water. (p45,46)
Sodium reacts violently with water and explodes while iron reacts slowly, rusting.
22.
How are mercury and sodium similar? (p46.47)
Mercury and sodium are both silver coloured and are metals.
23.
How are mercury and sodium different? (p46,47)
Sodium floats on water, reacts violently with water and explodes. Mercury reacts very little with water and sinks to the bottom of water because it is 13.6 times heavier.