Grade 7 Science — Metals and non-metals

1.Why does the chapter say that wood, glass and plastic are neither metals nor non-metals?

• a) Because they float in water, and metals and non-metals sink
• b) Because they are made in factories rather than dug out of the ground
• c) Because those two names are for elements, and these materials are not elements
• d) Because they are neither hard nor soft enough to be tested

2.Copper going green and silver going black are the same kind of slow damage that a brown deposit does to iron. What is the general name for a metal surface being eaten away like this by air, water or other substances?

3.An iron gate left out through a wet season grows a brown flaky deposit. What is that deposit called?

4.A gas made by burning a non-metal is dissolved in water. What nature would you expect that solution to have?

• a) Acidic
• b) Basic
• c) Neutral
• d) Basic first and then acidic

5.A spoonful of powder left after burning a metal is stirred into water. What nature would you expect that solution to have?

• a) Neutral
• b) Acidic first and then basic
• c) Acidic
• d) Basic

6.A hammer is brought down on a lump of coal and it shatters. What is the word for behaving that way?

• a) Sonorous
• b) Malleable
• c) Ductile
• d) Brittle

7.Which of these does the chapter say about how hard metals are?

• a) Some metals, such as sodium, are soft enough to cut with a knife
• b) The softest metals are the ones that conduct heat worst
• c) A metal is hard by definition, so a soft material is not a metal
• d) Metals grow harder the longer they are left in the open air

8.What has to reach an iron nail before a brown deposit forms on it?

• a) Dry air on its own
• b) Water and air together
• c) Sunlight and dry air
• d) Water on its own