Radioactivity Flashcards Preview

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Flashcards in Radioactivity Deck (13):
1

What is an ion?

An atom or molecule with a total positive or negative charge

2

What is an isotope?

Atoms of the same element with a different number of neutrons

3

What is an alpha particle?

A particle consisting of 2 protons and 2 neutrons, emitted from an unstable nucleus
When given off the mass number decreases by 4 and the atomic number decreases by 2

4

What is a beta particle?

A particle consisting of an electron emitted when a neutron in the nucleus turns into a proton
The mass number stays the same but the atomic number increases by 1

5

What are gamma rays?

High energy, high frequency waves
The energy is emitted and the mass and atomic numbers stay the same

6

What is ionisation?

When electrons are knocked out of an atom making them charged

7

Why is nuclear radiation dangerous?

If living cells become ionised then one of three things happens:
• the cell dies
• the cell repairs itself
• the cell mutates incorrectly and can become cancerous

8

What is gamma radiation a form of?

Electromagnetic radiation

9

What is a half-life?

The average time it takes for half of the nuclei present in a radioisotope to decay

10

What is irradiation?

When objects that are near a radioactive source are irradiated by it, but this doesn’t make the object radioactive

11

How can radioactivity be used?

• Radiotherapy:
- cancer treatment
- control/kill cancer cells
• Smoke alarms (alpha)
• Detecting underground leaks (gamma)
• Carbon dating (living wood containing radioactive carbon with a half-life if 5600 years)
• Uranium dating (finding the age of igneous rock)

12

What is nuclear fusion?

The joining of 2 nuclei to form a larger one
The nuclei collide and fuse together, emitting energy

13

What is nuclear fission?

The splitting of atoms
A neutron is fried at a large nucleus
The unstable isotope splits releasing energy and high speed neutrons