1.1

Question 1

define the atomic number

Answer 1

the number of protons in the nucleus of an atom of that element

Question 2

define mass number

Answer 2

the sum of the nucleus of protons and neutrons in the nucleus if an atom

Question 3

what are isotopes

Answer 3

atoms of the same element with different masses

Question 4

what does a mass spectrometer do

Answer 4

measures the mass of atoms and molecules using a magnetic field

Question 5

what is an M + 1 peak caused by

Answer 5

when the percentage of carbon-13 isotope becomes significant enough to be detected in large organic substances

Question 6

define relative atomic mass

Answer 6

the weighted mean mass of an atom of an element compared to the 1/12 of the mass of an atom of carbon -12

Question 7

define relative isotopic mass

Answer 7

the mass of an individual atom of a particular isotope relative to 1/12m of the mass of an atom of carbon-12

Question 8

what is the molecular ion peak

Answer 8

the peak with the highest m/z ratio in the mass spectrum, the M peak z-charge

Question 9

what is the shape of an ‘s’ orbital

Answer 9

spherical

Question 10

what is the shape of a ‘p’ orbital

Answer 10

elongated dumbbell shape and a variable charge density

Question 11

define a quantum shell

Answer 11

the energy level of an electron

Question 12

define electronic configuration

Answer 12

shows the number of electrons in each sublevel in each energy level of the atom

Question 13

define an orbital

Answer 13

a region within an atom that can hold up to two electrons with opposite spins

Question 14

what’s hunds rule

Answer 14

states that electrons will occupy the orbitals singly before pairing takes place

Question 15

what’s pauli exclusion principle

Answer 15

that two electrons cannot occupy the same orbital unless they have opposite spins

Question 16

what happens when electrons move back to the lower energy level

Answer 16

they emit electromagnetic radiation

Question 17

what’s the equation for first and second ionization energy

Answer 17

X(g) -> X+(g) + e-
X+(g) -> X2+(g) + e-

Question 18

what are the 4 factors that affect ionization energy

Answer 18

the orbital an electron is in
the atomic radius
the shielding
the nuclear charge of an atom

Question 19

explain the trend in ionization energy from hydrogen to helium

Answer 19

the increased nuclear charge makes it a lot harder to remove the electron as there is a stronger force of attraction, shielding is negligible

Question 20

define first ionization energy

Answer 20

the energy required to remove an electron from each atom in one mole of atoms in the gaseous state

Question 21

what is the trend in ionization energy between He and Li and why

Answer 21

first ionization of Li is lower than He as there is a new shell so increased shielding

Question 22

why has Ne got a lower ionization energy than He

Answer 22

its easier to remove an electron from a p orbital as its got a higher energy level

Question 23

define second ionization energy

Answer 23

the energy required to remove an electron from each singly charged positive ion in one mole of positive ions in the gaseous state

Question 24

how do you measure the atomic radius

Answer 24

the distance between the center of two nuclei divided by 2