They contain equal numbers of protons but different numbers of neutrons in their nuclei.
1 of 20
Substances that constantly emit radiation are said to be ...
Radioactive.
2 of 20
Describe the plum pudding model.
A sphere of positive charge, with negative electrons scattered amongst it
3 of 20
Describe the Rutherford scattering experiment.
An alpha particle was fired by a atom shooter, through golden foil, which was then detected by a Gieger counter.
4 of 20
Describe the results of Rutherford's experiment.
1)- Lots were detected behind the gold, they must have traveled straight through. 2)- Some were deflected. Positive alpha particle repelled. 3)- Few detected in front of gold. Alpha particle must've bounced off something.
5 of 20
What atom model replaced the plum pudding?
Nuclear atom.
6 of 20
Describe the difference between the nuclear atom, and the plum pudding model.
The plum pudding was a positively charged sphere, with electrons dotted around. Nuclear atom had a central nucleus, (which had solid matter), with electrons orbiting the nucleus in shells.
7 of 20
Describe alpha particles.
Two neutrons and two protons, the same as a helium nucleus. A sheet of paper stops alpha radiation, because the particle is so big. Slow moving. Highly ionizing.
8 of 20
Describe beta particles.
An electron from the nucleus, which has high energy (fast). Few mm, so Al can stop it. Weakly ionizing.
9 of 20
Describe gamma radiation.
It is electromagnetic radiation. Very small. Reduced by a few cm of lead. Very weakly ionizing. No mass/atomic no. 3x10^8m/s fast.
10 of 20
Alpha and beta radiations are deflected by both electric and magnetic fields but gamma radiation is not.
***
11 of 20
Alpha particles are deflected less than beta particles and in an opposite direction.
***
12 of 20
Describe the dangers of alpha radiation, inside the body.
Is most dangerous out of beta, and gamma radiation. It is easily absorbed by cells.
13 of 20
Describe the dangers of beta, and gamma radiation, inside the body.
Beta and gamma radiation are not as dangerous because they are less likely to be absorbed by a cell and will usually just pass right through it.
14 of 20
Describe beta, and gamma radiation outside the body.
Beta and gamma radiation are the most dangerous sources because they can penetrate the skin and damage the cells inside.
15 of 20
Describe alpha radiation outside the body.
Alpha radiation is not as dangerous because it is unlikely to reach living cells inside the body.
16 of 20
Describe half-life.
The half-life of a radioactive isotope is the average time it takes for the number of nuclei of the isotope in a sample to halve, or the time it takes for the count rate from a sample containing the isotope to fall to half its initial level.
17 of 20
What does Carbon14 deay into during radioactive decay?
Nitrogen14 - which explains why there is so much N in the atmosphere.
18 of 20
What is the difference between gamma decay, and beta/alpha decay?
Gamma does not change the atom. Beta, and alpha decay change the element.
19 of 20
Why is alpha radiation so ionizing?
It is a big particle, and slow, so there is more chance of colliding electrons from other atoms.
20 of 20
Other cards in this set
Card 2
Front
Substances that constantly emit radiation are said to be ...
Comments
Report
Report
Report