atomic structure 1.1, 1.2, 1.3, 1.5

Question 1

what did john dalton suggest + year

Answer 1

john dalton suggested that elements were made of indivisible atoms. atoms could not be broken down

1803

Question 2

what did ernest rutherford find + year

Answer 2

rutherford found that most of the mass and all of the positive charge of the atom was in a tiny nucleus

1911

Question 3

what did JJ thomson discover + year

Answer 3

thomson discovered the electron - the first sub atomic particle to be discovered. he showed that electrons were negatively charged and that electrons from all elements were the same
he also created the plum pudding model, he suggested that electrons were located within the atom in circular arrays (like plums in a pudding of positive charge)

1897

Question 4

what subatomic particles are atoms made of

Answer 4

protons
neutrons
electrons

Question 5

what’s in the nucleus, and what can they be called

Answer 5

protons, neutrons

they can be called nucleons because they are found in the nucleus

Question 6

what are the relative masses and charges of subatomic particles

Answer 6

proton: mass 1 charge +1

neutron: mass 1 charge 0

electron: mass 1/1840 charge -1

Question 7

what is the atomic number

and what is it also called

Answer 7

proton number

proton number Z

Question 8

what is the mass number

and what is it also called

Answer 8

number of protons + neutrons

mass number A

Question 9

atoms of the same element have the same number of what

what sub atomic particle determines what type of atom it is

Answer 9

protons

protons

Question 10

what are isotopes

Answer 10

atoms of the same element with the same number of protons but different number of neutrons

Question 11

what are protons and neutrons held together by in the centre of the atom

Answer 11

they are held together by a force called the strong nuclear force

Question 12

explain why we assume that there is the same number of protons and electrons in an atom

Answer 12

because in a neutral atom, their charge is equal in size and opposite in sign

Question 13

why do isotopes have the same chemical reactivity

Answer 13

different isotopes of the same element they have the same chemical reactivity because they have the same number of electrons

Question 14

define relative atomic mass

Answer 14

average mass of all isotopes of an element relative to 1/12 the mass of carbon 12

Question 15

what is an orbital

Answer 15

a region around the nucleus that can hold up to 2 electrons

Question 16

describe the relationship between 2 electrons in the same orbital in terms of their spin

Answer 16

they have opposite spins as they repel each other due to like charges (negative)

Question 17

explain why chromium does not fit the trend for electronic configuration

Answer 17

it only has 1 electron in its 4s orbital before filling 3d

-complete orbital is more stable than a partially filled orbital
-half filled orbital is more stable than a partially filled orbital

Question 18

what elements do not fit the electronic configuration trend

Answer 18

cu (copper)
cr (chromium)