The continuous expansion of the universe is due to

• separation of galaxies

• stability of galaxies

• approaching of galaxies

• slow of galaxies motion

Scientists believe that the matter of the universe was a .............ball of high temperature and pressure

• liquid

• solid

• gaseous

After minutes from the Big Bang, the temperature becomes...... million degrees

• 100

• 1000

• 10000

............began to form after 3000 million years of the Big Bang.

• Galaxies

• Stars

• Planets

The two gases which produced galaxies, stars and universe over millions of years are

• oxygen and helium.

• hydrogen and helium.

Within minutes after Big Bang, hydrogen gas was formed by a percentage of

• 25 %

• 50 %

• 75 %

Within minutes after Big Bang, helium gas was formed by a percentage of

• 75 %

• 65 %

• 55 %

• 25 %

The Milky Way galaxy took its disc form after about......million years from the big bang

• 1000

• 13000

• 5000

According to the Big Bang theory, within minutes from the origin of the universe, the ratio of hydrogen to helium is

• 75:1

• 25: 1

• 3:1

• 1:3

Planets rotate around the Sun by the effect of the gravity of

• the Sun.

• Jupiter.

• the Earth.