atomic structure

Question 1

atomic nucleus stucture

Answer 1

all atoms have a positively charged nucleus surrounded by a larger cloud of negatively charged electrons
the nucleus is made up of two subatomic particles- protons and neutrons

Question 2

mass and charge

Answer 2

AMU- atomic mass units
The subatomic particles have a certain mass and charge. The nucleus is overall positive as it is composed of positive protons, neutral neutrons, disregard the mass of an electron as it is negligible

Question 3

proton and neutron mass

Answer 3

1 AMU

Question 4

where are electrons with low energy

Answer 4

Electrons with low energy are in shells close to the nucleus

Question 5

where are electrons with high energy

Answer 5

electrons with high energy are in the outer shells, electrons in the same shell have about the same emergy

Question 6

max number of electrons calculation

Answer 6

the max number of electrons that a shell can hold can be calculated using 2n^2

Question 7

what is Aufbau

Answer 7

The aufbau principle states that lower energy shells must fill before higher ones

Question 8

valence electrons

Answer 8

the outermost shell is the valence shell

Question 9

what can the valence shell predict

Answer 9

can predict the chemical properties of the element and the bonds it will form because valence electrons are used in chemical reactions

Question 10

octet rule

Answer 10

atoms lose, gain and share electrons to achieve 8 valence electrons

Question 11

protons - notation

Answer 11

the no. of protons is the atomic number (Z)

Question 12

what is the mass number why is it a decimal

Answer 12

protons + neutrons (A)

mass number is decimal because of isotopes, rnd to nearest whole number

Question 13

what is no. of protons equal to

Answer 13

protons= electrons

Question 14

how to find no. of neutrons

Answer 14

mass number- atomic number

Question 15

notation

Answer 15

mass number top

atomic number bottom

Question 16

what r isotopes

Answer 16

atoms that have the same number of protons (atomic number) but different number of neutrons as known as isotopes. In nature atoms have different numbers of isotopes ie. gold has one isotope

Question 17

Electronic structure- quantum mechanical model

Answer 17

major energy levels in an atom are called shells (n), the max number of shells 2n^2

these shells contain separate energy levels of similar energy called subshells labelled s,p,d and f, each holding a certain no. of electrons

Question 18

how many electrons in each subshell?

Answer 18

s - 2
p - 6
d - 10
f - 14

Question 19

electronic structure

Answer 19

electrons therefore exist within subshells which themselves are within shells

eg.
shell 1 (n=1), there is only an s subshell holding max 2 electrons 
shell 2 (n=2), there is an s AND p subshell that hold 2 & 6 electrons, so the total electron number for n=2 is 8

Question 20

orbitals

Answer 20

hold 2 electrons
s- 1 orbital 
p- 3 orbitals 
d- 5 orbitals 
4s has less energy than 3d so aufbau says 4s will fill before 3d

Question 21

chromium and copper- exceptions to the rule

Answer 21

chromium - more stable to have a completely half filled d and ignore aufbau

copper - more stable to have a completely filled 3d and ignore aufbau

correct filling order- 4s then 3d
correct shell config. 3d then 4s

Question 22

orbital diagrams

Answer 22

orbital diagrams show individual electrons in their orbital boxes in their subshells, to help show the electron config. of an atom

Question 23

what is the pauli exclusion principle

Answer 23

no two electrons can occupy the same quantum position or state. Electrons in the same orbital must have opposite spin

Question 24

what is hunds rule

Answer 24

every orbital in a subshell is singly occupied before any orbital is double occupied