Ch - Elements and Compounds

Pure substances are the substances that have a fixed composition and are homogeneous.

• True

• False

Which of the following are pure subtances? (You can choose more than one corrcet answer)

• Noble gas

• Metals

• Compounds

• Homogeneous mixture

The substance shown in the picture is

• Metal

• Non-metal

• Metalloids

• Noble gas

State true or false:

Elements are made up of only one type of atoms.

Which of the following properties are correct for metals? (You can choose more than one correct answer)

• Metals are good conductor of heat and electricity.

• They are brittle and dull.

• They are non-ductile.

• They are malleable.

Which metal exist in liquid state at room temperature?

• Sodium

• Mercury

• Potassium

• Gold

Diamond is the hardest substance found on the Earth. Is it metal, non-metal or metalloid?

Which of the folllowing is used for disinfection of drinking water?

• Nitrogen

• Oxygen

• Hydrogen

• Chlorine

If you visit a market at night, you can see lots of colourful and bright signboards. Which of the following non-metal is used in signboards?

• Silicon

• Neon

• Carbon

• Hydrogen

Name the element which has properties of both metals and non-metals.