final revision part 1

During the chemical reaction, Mg ₁₂ loses its outer electrons and changes into..............

•          Mg^-    

• Mg^-2

•           Mg⁺²  

• Mg⁺         

Passengers are rushed back when the car moves suddenly because of................

•  centrifugal force  

•  gravitational force   

• force of inertia    

•   friction force

 If your car moves beside the stopping car you imagine that the other car moves.....................

• backwards

• at a high speed

• at the same speed

• forwards but slowly

Earth is located in the………………. Position according to its distance from the sun.

• third

• fourth

• fifth

• second

The celestial bodies that revolve between Mars and Jupiter are named……….

• Asteroids

• comets

• meteorites

• meteors

All of the following are covalent molecules except..............................

• H₂O        

•            O₂

•         MgO           

• HCl

……………… Is an example for mechanical waves.

• light waves

• radio waves

• microwaves

• sound waves

the biggest unit of the universe are..........................

• planets

• galaxies

• stars

• moons

Marble is an example of ......................rocks.

• igneous

• metamorphic

• sedimentary

the valency of Ca₂₀ is ..................

• monovalent

• divalent

• trivalent