P8 Space

Question 1

Planets in the solar system

Answer 1

Mercury
Venus
Earth
Mars
Jupiter 
Saturn
Uranus
Neptune
Pluto (dwarf planet)

Question 2

Natural satellites

Answer 2

Moons of a planet or dwarf planet

Our moon takes 27.3 days to obit us

Question 3

A star

Answer 3

Make their own light and have a strong gravitational field
When a protostar gets bigger and hotter from it gravitational field pulling in gas and dust. The core is so hot hydrogen gas fuses which releases energy and ignites the protostar in a massive nuclear reaction. A star is formed

Question 4

Planet

Answer 4

Spherical
In orbit of a star
Gravitational field strong enough to clear other material outer its orbit

Question 5

Dwarf planet

Answer 5

Spherical
Orbits a star
Gravitational field strength is too weak to clear other materials out of it orbit

Question 6

Moon

Answer 6

Orbits planets not stars

Question 7

Earths orbit

Answer 7

About 150 million km from the sun
Takes a year to orbit the sun
Almost circular orbit

Question 8

Artificial satellites

Answer 8

Obit the earth for communication, GPS, weather forecasts etc.
They are launched at right angles to the earth so that is stays within the gravitational field

Question 9

Nebulae

Answer 9

Huge clouds of dust, hydrogen, helium are sometimes the the birthplaces of stars

Question 10

Protostar

Answer 10

Over millions of years, the force of gravity pulls the gas and dust in the cloud together. As the vast cloud compresses it gets hotter until the core begins to glow.

Question 11

Nuclear fusion

Answer 11

When hydrogen atoms fuse together to produce large amounts of energy. The hydrogen repels other hydrogen atoms so to over come the high temperatures of 15000000 degrees Celsius must be created by the force of gravity compressing the gases

Question 12

Main sequence

Answer 12

When stars are at a stable state

Question 13

Forces in equilibrium

Answer 13

In main sequence stars forces are at equilibrium
Inward force from gravity
Outward force from fusion reactions

Question 14

Life cycle of stars

Answer 14

10billion year life
The time it takes for all the hydrogen to be bonded into helium
Forces change as helium fuses to create larger (heavier) elements
Although star could potentially collapse and explode if gravity was stronger than outward forces

Question 15

Red giant

Answer 15

Star has become unstable and outer layers of the star are pushed out to many times the stars original size

Question 16

Life cycle of a star

Answer 16

Nebula 
Protostar
Sun (main sequence)
Red giant 
White dwarf
Black dwarf

Question 17

Red super giant

Answer 17

3-50x bigger than sun.
Shorter life (millions not billions of years)
Hydrogen used up quicker and star expands & helium nuclei fuse to form larger nuclei of elements such as carbon and nitrogen. With each cycle temperature increases and more lighter nuclei fuse together

Question 18

Supernova

Answer 18

Fusion stops and the core collapses causing a gigantic explosion which blows the outer layers of the star into space. Distributes elements formed by fusion throughout universe.

Question 19

Neutron star

Answer 19

If the surviving core is between 1.5&3 solar masses it contracts to become very small and dense

Question 20

Black hole

Answer 20

If the core is greater than 3 solar masses the core contracts to become a black hole.

Question 21

The early universe

Answer 21

Only contained clouds of hydrogen with little helium. Clouds of gas were compressed by gravity to form the first stars. Hydrogen started to fuse together and form helium

Question 22

Making light elements

Answer 22

All elements up to iron are made bumpy nuclear fusion.
The larger the star the greater the range of elements
energy is not released when iron nuclei fuses they require energy to fuse together

Question 23

Making elements heavier than iron

Answer 23

When the star collapses the temperature becomes high enough for heavier elements such as gold and uranium to be formed. These heavier metals are then spread out and biome part of a new nebula

Question 24

Red shift

Answer 24

The greater the speed of the light source relative to the observer, the greater the change in wavelength of the light observed

Question 25

What did Edwin Hubble notice?

Answer 25

Light form distant galaxies had longer wavelengths than expected. Light has wavelengths shifted towards the red end of the spectrum

Question 26

An expanding universe

Answer 26

Degree if red shift was directly proportional to the distance of the Galaxy away from the earth. The further away a galaxy is from another galaxy, the faster it is moving away from it

Question 27

Big Bang

Answer 27

Suggests the universe was denser together before and Big Bang was the point in which it started to expand. Also suggests this dense region was extremely hot

Question 28

Dark matter

Answer 28

The mass of the visible star isn’t enough to hold the stars in orbit around the Galaxy. There must be extra matter that we can not see, which holds galaxies together by gravitational attraction

Question 29

Dark energy

Answer 29

Most of the mass/ energy of the universe must consist of something we know nothing about for the rate of expansion of the universe to appear to be increasing.

Question 30

Percentages of energy in the universe

Answer 30

4% visible matter
22% dark matter
74% dark energy