Atomic structure

Question 1

who discovered that atoms were the smallest building blocks of matter?

Answer 1

ancient greeks and John dalton

Question 2

who discovered electron and plum pudding model?

Answer 2

JJ Thompson

Question 3

who discovered neutron?

Answer 3

Chadwick

Question 4

Discovery of the nucleus? and how?

Answer 4

rutherford
bombarded gold foil with alpha particles and found that particles scattered. allowed to deduce that there is a positive nucleus repelling and colliding with particles.

Question 5

discovery of arrangement of electrons

Answer 5

Bohr

Question 6

define Atomic number

Answer 6

the number of protons in an atom of an element

Question 7

define mass number

Answer 7

the total number of protons and neutrons inside the nucleus of an atom

Question 8

define nucleons

Answer 8

protons and neutrons collectively in a nucleus

Question 9

define relative atomic mass

Answer 9

It is the mass of a particle on the scale where an atom of carbon-12 has a mass of 12

Question 10

define isotopes

Answer 10

Atoms of the same element having the same number of protons, but different number of neutrons

Question 11

define Hunds rule

Answer 11

Every orbital in a sub-level is singly occupied by electrons before any orbital is doubly occupied

Question 12

define paulis exclusion principle

Answer 12

Orbitals can accommodate a maximum of 2 electrons provided they spin in opposite directions

Question 13

define valence electrons

Answer 13

electrons in the outermost energy level of an atom that can participate in the formation of chemical bonds

Question 14

define orbitals

Answer 14

area in space surrounding the nucleus where an electron is most likely to be found

Question 15

what is Z

Answer 15

smaller number
atomic number and number of protons
and number of electrons

Question 16

what is A

Answer 16

bigger number
mass number
neutrons + protons

Question 17

3 isotopes of hydrogen and their neutrons

Answer 17

protium- 0 neutrons
deuterium- 1 neutrons
Tritium- 2 neutrons

Question 18

what is different in isotopes and what is the same?

Answer 18

everything same besides number of neutrons

Question 19

explain how to get relative atomic mass of isotopes

Answer 19

1. write down the isotopes and their percentages
2. Ar= put percentages over 100 and multiply by their mass number
3. do this for all and add
4. unitless answer

Question 20

explain how to calculate percentage abundance of isotopes?

Answer 20

1. write down isotopes and name smaller one p and other one 100-p
2. RAM= put p over 100 and multiply by mass number and put 100-p and multiply by mass number
3. add together and solve equation
4. write down the percentage abundance for each

Question 21

why do isotopes of an element have similar characteristics?

Answer 21

isotopes have same number of electrons, electrons involved in bonding. same number of electrons means same reactivity.

Question 22

energy of electrons close to nucleus?

Answer 22

low

Question 23

energy of electrons further away from nucleus?

Answer 23

high

Question 24

what does aufbau diagrams show

Answer 24

that within each energy shell there are orbitals at different energy levels

Question 25

draw aufbau template

Answer 25

increasing energy (vertical)
4s //
3p.  // // //
3s //
2p.  // // //
2s//
1s//

Question 26

define atomic orbital

Answer 26

region in which an electron may be found around a singe atom

Question 27

what is SP notation

Answer 27

electronic configuration- shortened version of aufbau diagrams