gr 10-chemistry (unit 2.5)

Question 1

what are isotopes

Answer 1

two or more forms of the same atom with the same number of protons but a different number of neutrons

Question 2

what happens if isotopes have more neutrons than protons

Answer 2

they have too much energy and become unstable

Question 3

what are unstable isotopes called

Answer 3

radioactive isotopes

Question 4

how do radioactive isotopes get rid of their excess energy

Answer 4

they emit particles from their nuclei

Question 5

what is radiation

Answer 5

a form of energy transfer in which atoms or molecules give off energy through electromagnetic waves

Question 6

nuclear decay

Answer 6

a change to an atom due to the emission of particles or radiation

Question 7

Alpha decay

Answer 7

when a nucleus emits an (a) particles resulting in two fewer neutrons and two fewer protons (4/2H)
the top number is the mass number and the bottom is the atomic number

Question 8

Beta decay

Answer 8

emits fast-moving (B) electrons
in this process, a neutron decays into a proton and an electron
eg. 8/3Li -> 8/4Be + 0/-1 +energy

Question 9

Gamma decay

Answer 9

after an alpha or beta decay, a nuclear is usually left in its excited state and is, therefore, unstable
to become stable the nuclear gives off a high energy photon called a gamma ray (y)

Question 10

nuclear fission

Answer 10

a heavier nucleus is split into smaller, lighter nuclei with the release of energy (breaks apart)

Question 11

nuclear fusion

Answer 11

form/mend together a slightly larger nucleus