atoms and molecules

Question 1

elements come in 3 states of matter

Answer 1

solids - metals
liquids - Hg & Br2
gases - diatomic and inert monoatomic

Question 2

allotropes

Answer 2

element that has different structural forms / connected in different ways

Question 3

atoms sub atomic particles

Answer 3

protons
electrons
neutrons

Question 4

atomic number

Answer 4

number of protons + number of electrons

Question 5

mass number

Answer 5

number of protons + number of neutrons

Question 6

protons

Answer 6

are positive with one unit of weight

Question 7

electrons

Answer 7

are negative and have practically no weight

Question 8

neutrons

Answer 8

are neutral with one unit of weight

Question 9

atomic number

Answer 9

total number of protons

Question 10

noble gases

Answer 10

helium
neon
argon
krypton
xenon

Question 11

noble gas

Answer 11

this has a complete outer electronic shell

Question 12

isotopes

Answer 12

atoms having the same value of protons but different values for neutrons

Question 13

anions

Answer 13

have a minus sign

Question 14

cations

Answer 14

have a positive sign

Question 15

pure substances

Answer 15

elements and compounds

Question 16

uncombined natural sources

Answer 16

silver Ag, gold Au, nitrogen N2, sulfur S

Question 17

oxides

Answer 17

chromite FeCr2O4, magnetite FeO4, water H2O, carbons dioxide CO2

Question 18

carbonates

Answer 18

limestone CaCO3, dolomite CaCO3MgCO3

Question 19

halides

Answer 19

salt NaCl, fluorite CaF2

Question 20

sulfides

Answer 20

galena PbS, cinnabar HgS

Question 21

phosphates

Answer 21

monazite La(PO4)

Question 22

covalent bond

Answer 22

sharing electrons between atoms

Question 23

ionic bonding

Answer 23

electrostatic attraction between oppositely chatted atoms

Question 24

covalent molecule examples

Answer 24

chlorine, iodine, carbon dioxide, methane, sulfur

Question 25

sublime

Answer 25

solid turning directly into vapour (iodine)

Question 26

ionic bonding

Answer 26

a transfer of electrons to achieve a filled shell

Question 27

ionic compound examples

Answer 27

NaCl sodium chloride, MgO magnesium oxide

Question 28

cations

Answer 28

these are positively charged species formed when neutral atoms low electrons

Question 29

anions

Answer 29

negatively charged species formed when a neutral atom gains electrons

Question 30

common cations

Answer 30

H+ , K+ , Cu+ , Cu2+

Question 31

common anions

Answer 31

Cl- , F- , S2-

Question 32

what ionises to give cations

Answer 32

metals

Question 33

what ionises to give anions

Answer 33

non-metals

Question 34

complex anions

Answer 34

NO3 nitric acid
(CO3)2- carbonate

Question 35

acids

Answer 35

HNO3 nitric acid
H2SO4 sulfuric acid
H3PO4 phosphoric acid

Question 36

what are bases

Answer 36

proton acceptors

Question 37

salts

Answer 37

formed by the replacement of the H+ ions of an acidic by another positive ion

Question 38

reaction of acids with bases

Answer 38

HCL + NAOH -> NACL + H2O

H2SO4 + 2KOH -> K2SO4 + 2H2O

HN03 + NH3 -> NH4NO3

Question 39

hydrogen bonding

Answer 39

the attraction between hydrogen atoms and either nitrogen, oxygen, or fluorine atoms

Question 40

hydrogen bonding strength

Answer 40

they have about 10th the strength of an average covalent bond and are constantly broken and reformed in liquid water

Question 41

how are salts formed

Answer 41

combining positive ions (cations) with negative ions (anions)

Question 42

what is a mole

Answer 42

the amount of substance which contains as many objects, atoms, molecules or things as the number of atoms in 12g of C12

Question 43

mass of an atom

Answer 43

in atomic mass units it is equal to the mass in grams of one mole of that element

Question 44

what is the number of objects in 1 mole called?

Answer 44

the Avogadro Constant (equal to 6.022 x 10^23 mol^-1)

Question 45

van der Waals forces

Answer 45

exist between non-polar molecules or atoms - weakest of all intermolecular forces