Atomic Structure

Question 1

relative charge of proton

Answer 1

+1

Question 2

relative charge of neutron

Answer 2

0

Question 3

relative charge of electron

Answer 3

-1

Question 4

relative mass of proton

Answer 4

1

Question 5

relative mass of neutron

Answer 5

1

Question 6

relative mass of electron

Answer 6

1/1840

Question 7

what are protons, neutrons and electrons

Answer 7

they are sub-atomic particles of an atom

Question 8

what is the factor that affects the chemical properties of an element

Answer 8

the number of valence electrons

Question 9

what is atomic number

Answer 9

proton number

Question 10

what is proton number

Answer 10

number of protons in an atom

Question 11

what is mass number

Answer 11

nucleon number

Question 12

what is nucleon number

Answer 12

total number of protons and neutrons in an atom

Question 13

what does 12 and 6 represent

Answer 13

12 is mass number
6 is proton (atomic) number

Question 14

isotopes definition

Answer 14

isotopes are atoms of the same element with the same number of protons and electrons but different number of electrons

Question 15

compare ³⁷Cl and ³⁵Cl

Answer 15

-both have 17 protons each
-chlorine—37 has 20 neutrons while chlorine—35 has 18 neutrons

Question 16

how to find neutron number

Answer 16

nucleon number — proton number

Question 17

how are ions obtained

Answer 17

when atoms gains or loses electrons

Question 18

3 descriptions of ions (atom gains or loses electrons)

Answer 18

-number of protons and neutrons remain the same
-mass number is the same
-only the number of electrons changes

Question 19

how are cations formed

Answer 19

loss of electrons
thus number of protons > number of electrons

Question 20

how are anions formed

Answer 20

gain of electrons
thus number of electrons > number of protons

Question 21

atom electrical charge

Answer 21

-an atom is electrically neutral
-because the number of positively charged protons is equal to the number of negatively charged electrons

Question 22

element, melting point/°C, electrical conductivity
lithium, 180.5°C, good
carbon (graphite), 3600°C, good
oxygen, —218.8°C, poor

Use ideas of structure and bonding to explain the differences in properties of the elements (6 points)

Answer 22

-Lithium has a giant metallic lattice structure, carbon(graphite) has a giant covalent structure and oxygen has a simple molecular structure.
-Large amount of energy is needed to break the strong covalent bonds between carbon atoms in graphite, hence it has a high melting point of 3600°C.
-Large amount of energy is needed to overcome the strong electrostatic forces of attraction between positively-charged ions and “sea of delocalised mobile electrons” in lithium, hence it has a high melting point of 180.5°C.
-Small amount of energy is needed to overcome the weak intermolecular forces of attraction, hence oxygen has a low melting point.
-Lithium and graphite conduct electricity due to the presence of mobile electrons.
-Oxygen does not conduct electricity as it does not have mobile ions or mobile electrons.