VIII SCIENCE QUICK REVISION

Which of the following set of elements have similar properties?

• O, S, Se

• O, F, Ne

• N, Ne, Na

• H, K, P

How do you calculate the number of neutrons?

• Mass number = Atomic number - Neutrons

• Mass number - Atomic number = Neutrons

• Atomic number = Neutrons

• Mass number = Neutrons

Salts that are made with hydrochloric acid are called ______________.

• chlorides

• sulfates

• nitrates

• carbonates

Why do you add excess of the insoluble reactant when making a soluble salt?

• To make sure all the acid is used up

• To separate the solid from the solution

• To make sure a reaction occurs

• To have the reaction happen faster

What will be reaction if less reactive metal is added in a solution with more reactive metal compound?

• vigorous reaction

• fizzing gas produced

• burns moderately

• no reaction

Complete the following equation

Lithium chloride + Iron → ?

• Lithium chloride + Iron (No change)

• Iron chloride + Lithium

• Lithium oxide + hydrogen

• Lithium oxide + oxygen

What is the genotypic ratio of the offspring is shown in the image?

• 25%

  75%

• 50%

  50%

• 25%

  50%

  25%

• 25%

  25%

  25%

  25%

Why are there no white rabbit babies in the image?

• The white gene is not present in any of the babies.

• It takes two recessive genes to show the characteristic.

• Grey is a better color.

• Baby five will be white.

The pressure of the gas in the balloon in the ice water will be:

• Greater than that of the balloon in the boiling water.

• Less than that of the balloon in the boiling water.

• The same as that of the balloon in the boiling water.

• Not enough information to answer the statement.

Army tank tracks are useful for travelling through the mud because_______________

• they decrease the force the vehicle exerts on the ground

• they increase the force the vehicle exerts on the ground

• they decrease the pressure the vehicle exerts on the ground

• they increase the pressure the vehicle exerts on the ground