Appendix 1.1

Question 1

what is a shell?

Answer 1

a shell is regarded as an energy level\the energy increases as the shell number increases
the shel number or energy level number is called the principle quantum number n

Question 2

number of electrons per energy level formula

Answer 2

2n^2

Question 3

atomic orbitals

Answer 3

atomic orbitals are regions in space in which there is a high possibility of finding electrons around the nucleus that can hold up to 2 electrons with opposite spins but no more
there are different types fo orbitals, called sublevels, s 1 orbital, p 3 orbitals, d 5 orbitals, f 7 orbitals all of which have different shapes. energy sub slevels correspond to a shape where elctrons are likely to be found

Question 4

electron

Answer 4

negative charge cloud

Question 5

aufbau principle

Answer 5

electrosn fill the lower energy orbitals first

Question 6

pauli exclusion

Answer 6

each orbital can hold 2 electrons with opposite spins

Question 7

electron configuation

Answer 7

the arrangemnet of eletcrons in an atom

Question 8

valence electrons

Answer 8

eelctrons ofund in teh outermost orbital of an atom.
group number corresponds to valence electrons
only valence electrons can participate in the formation of true chemical bonds
only el;ectrons involved when an atom undergoes chemical reactions
highest energy and furthest away from the nucelus

Question 9

number of shells

Answer 9

corresponds to period number

Question 10

hunds rule

Answer 10

within a sublevel, place on electron per orbital before pairing

Question 11

if a full shell implies stability then,

Answer 11

an elemnt having either 1 extra (alkali metals) or one less (halogens) should be very reactive

Question 12

octet rule

Answer 12

atoms tend to lose gain or share eletcron until they have 8 valence elctrons

Question 13

exceptions to octet rule

Answer 13

al b
h he

Question 14

most and least electronegative elments

Answer 14

most: flurotine
least: caseium francium

Question 15

cation

Answer 15

Metals tend to form cations.
Cations are elements having fewer electrons than protons.
Cations are positively charged atoms.

Question 16

anion

Answer 16

Nonmetals tend to form anions.
Anions are elements that have more electrons than protons.
Anions are negatively charged atoms.

Question 17

structure of atom

Answer 17

central nucelus consiting of posiitvely charged protons and neutrally charged neutrons
negatively charged electrons orbiting at a large distance from said nuceleus in increaisng energy levels

Question 18

isotope

Answer 18

variant of an element which differ in the number of neutrons they have. thus they have the same atomic numbers but not the same mass numbers

Question 19

charge and mass of an electron

Answer 19

relative charge: -1
relative mass: 1/1836

Question 20

atomic number: periodic tab;e

Answer 20

increases from left to right (accross the period) and increases up to down (down the group)

Question 21

atomic radius: periodic table

Answer 21

decreases from left to right (accross the period) due to increasing nuclear charge and increases up to down (down a group) due to more electron shells

Question 22

electrogentaivity: periodic table

Answer 22

incerases left to right (accrioss a period) due to decreasing atomic radius, decreases from up to down (down a group)

Question 23

meltinh and boiling point : periodic table

Answer 23

increases left to right due to more valence electrons and decreasing atomic radius, decreases down a group due to increased atomic radius

Question 24

radioactive isotope

Answer 24

ithe nucelus of a radioactive isotope is unstable and radiation is relased as it reorganises into a more stabel form

Question 25

radioactive isotope of carbon

Answer 25

carbon 14

Question 26

how do isotoppes differ in terms of chemical proepryes

Answer 26

seen as how isotopes have varying numbers of neutrons, isotopes have th exact same chemical properties as chemical properties are governed by the number and arrangment of the elctrons which is the same accross all isotopes

Question 27

brief history of the atom

Answer 27

democritus, an ancient greekk philosophe risggested the concept of the atmomos (indivissible), the samllest possible bit of a susbatnce after it has been vut numrous times. he thought that al things were made of the sa,me basic maetraisl bu that atoms of different susbtances had sifferent shapes and sizes, these theories did not account for any tangible laws and could not be tested for validity, they were puely theories. later on, john dalton would suggest additons to the greek idea of invisible atoms: atoms of a particular elemnt are all the same, atoms of different elements have differnet sizes and properties, compounds are forme dwhen atoms fo different elements combines togetehr in simple whoe number ratios and chemical changes involve the rearranging of atoms. this theory explained known facts, could be used to make prediction and could also be tested. it aso accounted for two existing chemical laws, constant comp ,and conversation of mass

Question 28

daltons theories

Answer 28

atoms of different elements have differnet sizes and properties, compounds are forme dwhen atoms fo different elements combines togetehr in simple whoe number ratios and chemical changes involve the rearranging of atoms.

Question 29

law of constant composition

Answer 29

however, you make a compound, it will lways have the same elements in the same proportions by mass

Question 30

law of conservation of mass

Answer 30

atoms can neitehr be destroyed nor created, thus, the mass of all the reactants of a chemical reaction must equal the mass of all the products

Question 31

atomic size: periodic table

Answer 31

decreases left to right (across the period) increases up to down (down a group)

Question 32

Reactivity: periodic table

Answer 32

Metals- decreases left to right increases up to down Non metal are the opposite of metals