The Atom Flashcards
Describe an atom
An atom is made up of protons, positively charged, neutrons, neutrally charged, and electrons, negatively charged
Which is the most reactive halogen, why and describe the pattern
Fluorine is the most reactive because it only needs 1 more electron to become stable. The halogen reactivity decreases as you go down the group
What are isotopes?
Isotopes are time that have the same atomic number but different mass numbers
Give an example if an isotope if hydrogen
Protium
Why are some elements radioactive?
Elements that are unstable want to gain or lose electrons to become more stable, so therefore they will give out ionising radiation which is radioactive, in order to gain the electrons
What do atoms give out to become more stable?
They give out ionising radiation which could be alpha particles, beta particles or gamma rays
What is an alpha particle
Alpha particles have 2 protons and 2 neutrons. It is the same as a helium nucleus
They abuse the mass (larger, on top) number to go down by 4 and the atomic number go down by two
What is a beta particle?
It is a fast moving electron emoted from he nucleus when a neutron changes to a proton
They do not affect the mass number but causes the atomic number to go up by 1
What is gamma radiation
Gamma radiation is when gamma rays are enjoyed from an unstable nucleus, they have short wavelengths
It had no effect on the mass or atomic number
219 Rn will become?
86
215 Po + 4 a
84. 2
14 C will become?
6
14 N + 0 B
7. -1
What are becquereles?
The measurement of how much radioactivity is given out by a substance
What is radioactive decay?
A random process where the nucleus will decay, so then the unstable nuclei decrease and the activity of the radioisotope decreases too
What is a half life
The time it takes for an activity to halve, eg the time for half of the nuclei to decay. It can be use to say how long it will be until a radioactive material is safe
