Theme one - Radioactive decay

Question 1

Define element

Answer 1

A pure chemical substance characterized by the number of protons present

Question 2

what is Z in an atom?

Answer 2

The atomic number (amount of protons)

Question 3

What is A in atoms?

Answer 3

The total number of protons + neutrons (mass number)

Question 4

What is relative atomic mass?

Answer 4

the ratio of the average mass of atoms in an element in relation to 1 hydrogen atom. (the weight of 1 mol of a substance is its relative atomic mass)

Question 5

What is radioactive decay?

Answer 5

the process by which unstable nucleotides/atoms transform into other stable/unstable isotopes via the admittance of alpha,beta particles, or gamma radiation

Question 6

What is atomic mass unit?

Answer 6

a mass equal to 1/12th of the mass of a C12 atom

Question 7

how do parent radionuclide decay?

Answer 7

Via a radioactive decay series

Question 8

How does a daughter element differ from a parent element when radioactive decay occurs via alpha particle emisssiom?

Answer 8

An atomic number (z) two less than parent, and mass number (a) 4 less

Question 9

what is an alpha particle?

Answer 9

A hydrogen atom ( two protons and two neutrons)

Question 10

what is a beta particles? how do they form?

Answer 10

a high speed electron that is emitted when a neutron in the nucleus is converted to a proton

Question 11

how do daughter isotopes differ from parent isotopes in beta decay?

Answer 11

unchanged mass number, atomic number 1 greater than parent

Question 12

what are the three isotopes oh hydrogen and which are unstable?

Answer 12

1H, 2H (deuterium, stable)
3H(titrium, unstable)
All have one proton

Question 13

How does 3H form in the atmosphere?

Answer 13

naturally in the upper atmosphere via cosmic ray bombardment, or artificially via nuclear weapons/power

Question 14

what are the two (out of 9) stable isotopes of carbon?

Answer 14

12C and 13 C

Question 15

How many of carbon atoms are unstable and how many protons do they have?

Answer 15

7 unstable with 6 protons. 14C is commonly used for dating methods

Question 16

how many isotopes of uranium are there? how many protons and how many are unstable?

Answer 16

9 isotopes each with 92 protons. ALL are unstable. 3 are natural (238U,235U,234U)

Question 17

Which form of uranium has a 17 step decay series?

Answer 17

238U

Question 18

what are nuclear forces and how do they impact atom stability?

Answer 18

forces that act between two or more nucleons, binding protons and neutrons into an atomic nuclei. Stable atoms have BALANCED NUCLEAR FORCES

Question 19

how does mass impact atom stability?

Answer 19

atoms with lower masses are generally more stable. .

Question 20

what ratio dictates isotope stability?

Answer 20

The neutron/proton ratio. this is variable between species.

Question 21

What are the ideal neutron to proton ratios for large and small isotopes?

Answer 21

Small= 1:1
Large= 1:1.5

Question 22

what is the stability zone and how does this influence half life?

Answer 22

The stability zone is the zone in which isotopes have the correct neutron:proton ratio to remain stable, and the further away from this the lesser the atom half lives.