Physics 3: stars and space

Question 0

How are heavy elements formed?

Answer 0

When a massive star collapses on I steal then explodes as a supernova.
The small nuclei get fused into elements larger than iron.

Question 1

How are light elements formed?

Answer 1

In a result of fusion in stars.

Question 2

What is the heaviest natural element?

Answer 2

Uranium

Question 3

What is uranium a half life?

Answer 3

4500 million years

Question 4

What is SETI?

Answer 4

Search for extra terrestrial intelligence.

Question 5

Why is carbon an important element?

Answer 5

It is in everything living.

Question 6

How is carbon formed?

Answer 6

When stars like the sun fuse hydrogen nuclei or protons together.

Question 7

What does a red giant fuse together?

Answer 7

Helium and other small nuclei into larger nuclei

Question 8

Elements as heavy as iron are formed because of…?

Answer 8

Nuclear fusion inside stars.

Question 9

Elements heavier than iron are formed in…?

Answer 9

Supernovas.

Question 10

What is the sequence of a low mass star?

Answer 10

Prostar
Main stage
Red giant 
White dwarf
Black dwarf

Question 11

What is the sequence for a high mass star?

Answer 11

Prostar 
Main stage
Red giant
White dwarf
Neutron star
Black hole if there is sufficient mass

Question 12

What is a pro star?

Answer 12

Particles of dust as has gathered under their own gravity

Question 13

What happens for a pro star to become a star?

Answer 13

The pro star becomes denser
Gets hotter
Nuclei of hydrogen atoms and other Light elements fuse together
Energy is released
Core gets hotter and brighter
A star is made

Question 14

Why do stars radiate energy?

Answer 14

Because of fusion in the core.

Question 15

Why does fusion keep happening in the core of a star?

Answer 15

As energy released keeps the core hot so fusion can continue. Radiation flows steadily in all directions from the core.

Question 16

Why will a star eventually swell out?

Answer 16

It runs out of hydrogen nuclei to fuse together.

Question 17

Why don’t stars collapse under their own gravity?

Answer 17

The force of gravity which makes a star contract is balanced by the outward pressure of radiation from its core. These stay balanced until the hydrogen nuclei have fused together.

Question 18

As a star swells out, what does it turn into?

Answer 18

A red giant.

Question 19

What occurs at the red giant stage?

Answer 19

Light elements fuse in the core to form heavier elements

Question 20

What happens when there is no more light elements in the core of a red giant?

Answer 20

Fusion stops
No more radiation is released
The star collapses on itself
It heats up and becomes a white dwarf

Question 21

What are two characteristics of a white dwarf?

Answer 21

Hot

Dense

Question 22

What is a supernova?

Answer 22

An explosion after the White dwarf stage if the star has a high mass

Question 23

What remains after a supernova occurs?

Answer 23

The core is compressed into a neutron star

If the star is large enough it becomes a black hole

Question 24

What is a neutron star?

Answer 24

Extremely dense object only made of neutrons

Question 25

What happened as the universe expanded?

Answer 25

It cooled and uncharged atoms were formed.

Question 26

What force pulled matter into galaxies and stars?

Answer 26

Gravity

Question 27

What are galaxies and stars made from?

Answer 27

Uncharged atoms

Question 28

How many years ago did the Big Bang happen?

Answer 28

13 thousand million years ago.