Science Quiz for Grade 8

What is the process of replacing a less reactive element with a more reactive one in a compound called?

• Substitution reaction

• Combination reaction

• Decomposition reaction

• Displacement reaction

Which metal is more reactive: gold or sodium?

• Sodium

• Carbon

• Gold

• wood

What is the product formed when magnesium reacts with water?

• Magnesium oxide

• Magnesium hydroxide

• Magnesium chloride

• Magnesium sulphate

What is the role of phenolphthalein in the reaction of magnesium with water?

• To accelerate the reaction

• To indicate an alkaline solution

• To slow down the reaction

• To neutralize the solution

Which metal can displace hydrogen from hydrochloric acid?

• Zinc

• Copper

• Gold

• Silver

Phenolphthalein show ……………. colour in alkali.

Magnesium displaces hydrogen from water to form …………………

A ……………………reaction is used to weld railway track.

Indigestion due to excess HCl is treated with ………………..

Name the metals around magnesium which are more reactive than magnesium