Chemistry

Question 1

what is the difference between an element, compound and a mixtrue

Answer 1

an element is only one element wheather a compound is multiple elements chemicaly bonded and a mixture is multiple elements that don’t bond

Question 2

what is the key to balancing equation:

Answer 2

same number of elements in the reactants as the products for example
2H02-> 2h+ 2O

Question 3

what are four types of seperation meathods

Answer 3

chromotography, distalation. evaporation. filtration.

rember cdef

Question 4

what is distillation

Answer 4

when something is boiled and then cooled to seperate the mixture

Question 5

what is the plum pudding model

Answer 5

a ball of positive charge with negative electrons embedded into it.

Question 6

how was the nucelaus discovered.

Answer 6

when firing alpha particles at a thin piece of gold the particles should not go through it meaning that the has to be a negative charge on the outside

Question 7

what is the charge of a proton, neutron and an electron

Answer 7

an electron is negative

a proton is positive and a neutron is netural with no charge

Question 8

what is the charge of a proton, neutron and an electron

Answer 8

an electron is negative

a proton is positive and a neutron is netural with no charge

Question 9

how to work out amount of protons electrons and neutrons

Answer 9

for electrons and protons it is the mass number unless it is an ion showing the charge in which case add if it says minus 4 charge then add to the the atomic number and the same for if it says negative then add to the atomic number
for protons it is always the atomic number
and for neutrons it is the total mass - the atomic number

Question 10

what is an ion and isotope

Answer 10

an ion is when an atom has a different amount of electrons than protons
isotopes are when an atom has a different number of neutrons

Question 11

how many electrons can be in the first three shells

Answer 11

2 in the first 8 in the next and again 8 in the next

Question 12

which group has no reactions and why

Answer 12

group zero/8 because all have a full shell which means the atom does not have the urge to complete its shell as it is already complete. this applies to all except helium.

Question 13

who invented the periodic table

Answer 13

Mendeleev

Question 14

how did he do it when not all elements were discovered

Answer 14

he left gaps for them so that he could be able to

Question 15

group zero has what properties

Answer 15

it is stable and has 8 electrons in its shell and are called the noble gases:

Question 16

what is group one called and what properties does it have

Answer 16

Alkalai metals are very reactive weak and bristle and get more reactive down the group. they also react to water and gasses

Question 17

group 7 is called what and has what properties

Answer 17

it has the properties of being incredibly reactive and getting less reactive the more it goes down.called the halogens

Question 18

covalent bonding is what

Answer 18

is the bonding between metals and non metals when non metals tend to gain electrons