Chapter 20-Elements, Compounds And Mixtures

Question 1

Elements

Answer 1

Substances made up of the same atoms

Question 2

Molecule

Answer 2

Two atoms chemically combined

Question 3

Compounds

Answer 3

Two/ more elements chemically combined eg. The salt NaCl

Question 4

Properties of compounds

Answer 4

• single substance
• elements always in a fixed ratio
• difficult to seperate
• heat change usually neccesary
• loose individual properties

Question 5

Matter

Answer 5

Anything that occupies space and has mass

Three states - solids, liquids and gasses

Question 6

Properties of mixtures

Answer 6

• two/more substances
• amounts vary
• usually easy to seperate
• very little heat involved
• dont loose their own individual properties

Question 7

Describe the difference between a mixture of iron and suflur and Iron Sulfide (FeS)

Answer 7

Mixture
-out magnet to iron fillings and they’ll come right out :)

Compound FeS

• put the mixture into a test tube and heat till it stops glowing red
• when it turns grey it is iron Sulfide (FeS)
• a magnet can no longer seperate them

Question 8

Compound vs. Element difference in Table salt

Answer 8

• NaCl
• sodium -very reactive metal
• chlorine-poisonous gas

Question 9

Compound vs element difference in Co2 in fire extinguishers

Answer 9

Co2 puts out fire

• carbon- black solid
• oxygen-needed to burn fuel

Question 10

Water

Compound vs mixture difference

Answer 10

H20
H=hydrogen -explosive gas
O= Oxygen- needed to burn fuel