1The List Below Contains Some Elements and Some Compounds

HELP

1The list below contains some elements and some compounds.

aWrite them into a table like the one shown. The first has been done for you.

Substance / Element or compound
Fe / Element

bWhich substances contain more than two atoms?

cWhich one is an element made from molecules?

dWhich ones contain both a metal and a non-metal?

eWhich compounds contain only non-metals?

2Copy and complete the following sentences:

aA molecule is ...

bA compound is ...

cA substance represented by a symbol must be an ...

This worksheet may have been altered from the original on the CD-ROM.

CORE

3Look carefully at the information in the table below.

Substance / Symbol or formula / Melting point (°C) / Appearance / Hazard symbol
Magnesium / Mg / 650 / Shiny grey solid /
Oxygen / O2 / –219 /
Magnesium oxide / MgO / 2852 / White powder

aWhat does the hazard symbol for magnesium tell you?

biSay whether magnesium oxide could be safe to use in a medicine.

iiExplain how you know.

ciDescribe one thing about magnesium and oxygen that is similar.

iiDescribe one way in which magnesium and oxygen are different.

diDraw a diagram showing how the atoms might be arranged in magnesium oxide.

iiOxygen is a molecule made from two oxygen atoms. Draw a diagram showing what a few oxygen molecules might look like.

EXTENSION

4Look at diagrams A to E.

aWhich diagram could represent copper chloride?

bWhich diagram could represent a solid metal element?

cWhich diagram represents an element made of molecules?

diWhich two diagrams represent the same element?

iiExplain your choice.

iiiIn what way are the two substances you chose different?

eWhich substance is an element but not a molecule?

fWhich three diagrams represent a solid element, a gaseous element and the compound that is made when they react together?

This worksheet may have been altered from the original on the CD-ROM.