Atomic Structure

Question 1

what are atoms?

Answer 1

smallest component of an element having the same chemical properties of that element

Question 1

why are atoms electrically neutral?

Answer 1

no. of p = no. of e

Question 2

how do sub-atomic particles behave in an electric field?

Answer 2

protons:
deflected towards negative plate

neutrons:
no charge, thus they remain unaffected

electrons:
deflected towards positive plate, much lighter than protons; deflected to a larger extent

Question 3

what is nucleon/mass number?

Answer 3

total number of protons and neutrons in nucleus of an atom

Question 4

what is atomic/proton number?

Answer 4

number of protons found in nucleus of atom

Question 5

what is electronic structure?

Answer 5

arrangement of electrons in the different electron shells of an atom

Question 6

what is valence/outermost shell?

Answer 6

shell farthest from nucleus

Question 7

what are valence electrons?

Answer 7

electrons in valence shell

Question 8

what are properties of electron shells?

Answer 8

nearer the shell to the nucleus, lower the energy level (shells filled in order of increasing energy level)

each shell numbered 1, 2, 3… outwards from nucleus

*valence electrons determine chemical properties

Question 9

what are groups and periods?

Answer 9

groups (1, 2, 13-18) (vertical): same no. of valence electrons

periods (horizontal): same no. of electron shells

Question 10

what are isotopes?

Answer 10

atoms of the same element with the same number of protons but different number of neutrons

Question 11

what changes are there to the properties of isotopes?

Answer 11

identical chemical properties as the number of valence electrons is the same

different physical properties as they have different masses due to a different number of neutrons

Question 12

what are ions?

Answer 12

atom or group of atoms that have an electrical charge

Question 13

what is the charge of sodium?

Answer 13

Na⁺

Question 14

what is the charge of calcium?

Answer 14

Ca²⁺

Question 15

what is the charge of oxygen?

Answer 15

O²⁻

Question 16

what is the charge of nitrogen?

Answer 16

N³⁻

Question 17

what is the charge of sulfate?

Answer 17

SO₄²⁻

Question 18

what is the charge of carbonate?

Answer 18

CO₃²⁻

Question 19

what is the charge of nitrate?

Answer 19

NO₃⁻

Question 20

what is the charge of hydrogen?

Answer 20

H⁺

Question 21

why are noble gases extremely unreactive?

Answer 21

noble gas configuration, making them very stable

Question 22

how are cations formed?

Answer 22

atoms of metals tend to form cations by losing their valence electron(s) to attain the noble gas configuration

*groups 1, 2, 13
*easier to gain 1-3 than to lose 5-7
*positive charge arises as there are more protons than electrons

Question 23

how are anions formed?

Answer 23

atoms of non-metals tend to form antions by gaining valence electron(s) to attain the noble gas configuration

*groups 15-17
*easier to lose 1-3 than to gain 5-7
*negative charge arises as there are more electrons than protons