atomic structure and periodic table

Question 1

what is an ion?

Answer 1

an atom which has lost or gained electrons to obtain a full outer shell, and therefore has a positive or negative charge

Question 2

what is an isotope?

Answer 2

an element with a different number of neutrons

Question 3

when does the division between metals and non metals begin?

Answer 3

Above Aluminium and Below Boron

Question 4

what is the mass and charge of a proton?

Answer 4

1 and 1+

Question 5

what is the mass and charge of a neutron?

Answer 5

1 and 0 ( has no charge )

Question 6

what is the mass and charge of an electron?

Answer 6

nearly zero and 1-

Question 7

when was it discovered that the atom was small particles and by who?

Answer 7

1803 - John dalton

Question 8

when was the electron discovered, inspiring the plum pudding model and by who?

Answer 8

1897 - JJ thompson

Question 9

when was the atom discovered to be mainly free space with a dense nucleus and by who?

Answer 9

1908 - Ernest Rutherford and co workers ( Hans geiger and Ernest Marsden )

Question 10

when was the proton discovered, inspiring the nuclear model and by who?

Answer 10

1911 - Ernest Rutherford ( himself )

Question 11

when were electron shells discovered and by who?

Answer 11

1914 - Neils bohr

Question 12

when was the neutron discovered and by who?

Answer 12

1932 - James chadwick

Question 13

what did Johann dobereiner do?

Answer 13

sort the elements by atomic weight in groups of 3, called the trains, but most elements didn’t fit the groups

Question 14

what did John newlands do?

Answer 14

sort the elements by atomic weight into groups of 8 called the law of octaves, believed the 8th elements was a repeat of the first, didn’t work after 17 elements

Question 15

what did dmitir mendeleev do?

Answer 15

sort elements by atomic weight and similiar chemical properties, and into groups and periods, left gaps for undiscovered elements

Question 16

what did Henry Mosley do?

Answer 16

say elements should be sorted by atomic number, not weight

Question 17

properties of group 0, the noble gases?

Answer 17

they are inert (unreactive), full outer shell, stable, as you go down group 0, the boiling point increases

Question 18

describe properties of group 1 elements, alkali metals

Answer 18

soft, reactivity increases going down but mp and bp decreases

Question 19

describe properties of group 7 elements, the halogens

Answer 19

move around in pairs, mp and bp increases as you go down, reactivity decreases as you go down

Question 20

why does reactivity decease going down group 7?

Answer 20

the force of attraction weakens, the positive nucleus and negative electrons in the outer shell get further apart from each other ( due to more electron shells ) this weakened force makes it harder for the element to gain an extra electron in it’s outer shell, making the element less reactive, it’s the opposite for group 1, it’s easier to lose it’s outer electrons to react