atomic structure and periodic table

Question 1

what do atoms have a radius of

Answer 1

about 0.1 nanometer (that’s 1x10^-10 metres

Question 2

describe the structure of an atom use the terms proton, neutron, electron, nucleus and shell in answer

Answer 2

atoms have a small nucleus surrounded by electrons. The nucleus is in the middle of the atom and contains protons and neutrons. The electrons occupy shells around the nucleus

Question 3

what is the relative size of the nucleus compared to the atom

Answer 3

the nucleus is about 1/10,000 the size of an atom

Question 4

whats the relative charge of :
proton
neutron
electron

Answer 4

proton: +1
neutron: 0
electron: -1

Question 5

what is the relative mass of a proton

Answer 5

1

Question 6

are atoms uncharged particles?. Explain why

Answer 6

Theyre uncharged particles as they have the same number of protons as electrons and protons and electrons have opposite chargers of the same size, so cancel each other out

Question 7

how does an atom become an ion

Answer 7

if some electrons are added or removed the atoms become charged and is then an ion

Question 8

what decides what type of atom it is

Answer 8

its the number or protons in the nucleus that decides what type of atom it is

Question 9

an atom w one proton in its nucleus is hydrogen

Question 10

an atom w two protons is helium

Question 11

whats an ion?

Answer 11

its an atom or group of atoms that has lost or gained electrons

Question 12

definition of acid

Answer 12

a substance that releases h+ ions in water (pH<7)

Question 13

give examples of bases

Answer 13

sodium hydroxide - NaOH, potassium hydroxide - KOH, calcium hydroxide - Ca(OH)2, ammonia - NH3

Question 14

definition of base

Answer 14

a substance that reacts with an acid to form a salt

Question 15

whats a alkali

Answer 15

a soluble base (pH>7)

Question 16

whats an indicator

Answer 16

a chemical that changes colour depending on whether it’s an acid or alkali

Question 17

what does metal oxide + acid go to
e.g. copper oxide + sulfuric acid –> ….

Answer 17

metal oxide + acid —> salt + water
copper oxide + sulfuric acid –> copper sulfate + water

Question 18

why will reacting a metal oxide with an acid not produce an alkali solution

Answer 18

when reacting a metal oxide with an acid, it will not produce an alkali solution due to the excessive metal oxide not reacting

Question 19

metal + acid –> ….
magnesium + sulfuric acid –>

Answer 19

metal + acid –> salt + hydrogen (MASH)
magnesium + sulfuric acid –> magnesium sulfate + hydrogen

Question 20

metal carbonate + acid –>
magnesium carbonate + sulfuric acid–>

Answer 20

metal carbonate + acid –> salt + water + carbon dioxide
magnesium carbonate + sulfuric acid –> magnesium sulfate + water + carbon dioxide

Question 21

metal hydroxide + acid –>
sodium hydroxide + hydrochloric acid –> …

Answer 21

metal hydroxide + acid –> salt + water
sodium hydroxide + hydrochloric acid –> sodium chloride + water

Question 21

how was Mendeleev’s periodic table arranged

Answer 21

arranged in order of atomic weight - however some elements were swapped over to fit with the properties of other elements in the group
left gaps

Question 21

why did Mendeleev leave gaps in periodic table

Answer 21

Mendeleev predicted properties of undiscovered elements and when they were discovered, his predictions were correct

Question 22

why weresome scientists skeptical about Mendeleevs table

Answer 22

because he mixed metals and non metals and some boxes contained two elements

Question 23

what ions did metals have

Answer 23

positive ions

Question 24

what ions do non metals have

Answer 24

negative ions

Question 25

how is the modern periodic table arranged

Answer 25

ordered in increasing atomic number

Question 26

why do things in the same group react in a similar way

Answer 26

they have the same number of outer shell electrons

Question 27

periodicity definition

Answer 27

a repeating pattern of properties at regular intervals

Question 28

# tip - metallic bonding why do metals have a high melting point

Answer 28

a lot of energy is needed to overcome the strong electrostatic force of attraction between metal ions and delocalised electrons

Question 29

why r metals a good electrical conductor

Answer 29

delocalised electrons can move and carry charge

Question 30

why r metals malleable/ductile

Answer 30

positive metal ions are arranged in neat rows that can slide past each other whilst remaining bonded

Question 31

# tip - covalent bonding why do non metals have low melting points

Answer 31

not a lot of energy is needed to overcome weak intermolecular forces between molecules

Question 32

# tip - covalent bonding why r non metals electrical insulators

Answer 32

molecules have no overall charge - no charged particles are free to move

Question 33

why might noble gases be used for filling lightbulbs

Answer 33

they have no need to gain or lose electrons as they have full outer shells of electrons this means they r inert

Question 34

what do noble gases exist as

Answer 34

monatomic gases .they exist as gases at room temp due to weak forces between atoms

Question 35

why does boiling point increase down the group (0/noble gas)

Answer 35

increases due to atoms increasing in size (increasing atomic number) so forces r stronger so more energy is needed

Question 36

alkali solution is due to prescence of what

Answer 36

alkali solution is due to the prescense of hydroxide (*OH-) ions

Question 37

metal + water -->

Answer 37

metal + water --> metal hydroxide + hydrogen

Question 38

metal + chlorine --> e.g. 2Na + Cl2 -->

Answer 38

metal + chlorine --> metal chloride 2NaCl

Question 39

Metal + oxygen --> e.g. 4K + O2 -->

Answer 39

metal + oxygen --> metal oxide 4K + O2 --> 2K2O

Question 40

As group 1 (alkali metals) increase in atomic number (down group) what happens to : density strength melting point reactivity

Answer 40

density increases strength increases melting point decreases reactivity increases

Question 41

what does reactivity depend on

Answer 41

depends on how easily the outer electrons is lost to form a 1+ ion

Question 42

why does reactivity increase down group 1 (alkali metals)

Answer 42

increased atomic radius - outer electron is further from nucleus increased electron shielding - more full electrons shells between the outer electron and nucleus decreased nuclear attraction to outer electron so it is more easily lost

Question 43

what do group 7 (halogens) exist as

Answer 43

diatomic molecules when each atom shares 1 electron in the covalent bond

Question 44

down group 7 (halogens) why does melting + boiling point increase

Answer 44

as the molecules increase in mass the intermolecular forces increase in strength so more energy is needed to overcome them

Question 45

what do halogens react w metals to form and what bonding does it have

Answer 45

to form halide ions (F-,BR- ect) by gaining an electron the product has ionic bonding

Question 46

when halogens react w non metals what molecules does it form e.g. H2 +Cl2 -->

Answer 46

form covalent molecules e.g. H2 + Cl2 -> 2HCl

Question 47

what does the more reactive halogen displace

Answer 47

more reactive halogen displaces the less reactive of halogen from a compound

Question 48

order of these most reactive - least reactive iodine,chlorine.astatine.bromine

Answer 48

most reactive chlorine bromine iodine least reactive astatine

Question 49

what would happen to this equation if displacement happened: KBr + Cl2 -->

Answer 49

KBr + Cl2 --> 2KCl + Br2

Question 50

when halogens react what do they gain

Answer 50

when halogens react they gain an electron

Question 51

why does reactivity decrease down group 7 (halogens)

Answer 51

atomic radius increases - electron gained is further away from nucles electron shield increases - more full electron shells between nucleus and electron to be gained weaker force of attraction between nucleus and electron to be gained so therefore gaining of electron is harder

Question 52

what r properties of transition metals (list 5)

Answer 52

high melting point,high density, high strength, high hardness, low reactivity

Question 53

why is iron used for construction

Answer 53

hard and strong + low reactivity

Question 54

definition of catalysts

Answer 54

substance that speeds up rate of a reaction without being used up