Structure Of The Atom

Question 1

What is the Atomic Number? (3)

Answer 1

• Unit = Z
• Number of Protons
• Decides the element

Question 2

What is the Mass number? (3)

Answer 2

• Unit = A
• Number of Protons & Neutrons
• Neutrons = A - Z

Question 3

X is the symbol of an element. What goes on top and what on the bottom? (2)

Answer 3

• Mass number on top (A)

- Atomic number on bottom (Z)

Question 4

What are Isotopes? (2)

Answer 4

Isotopes are different atoms of the same element with same atomic number but different mass numbers.

Question 5

Relative Atomic mass? (2)

Answer 5

• (Ar)

- Is a number that compares the average mass of an atom to the mass of the C-12 atom taken to be 12 units.

Question 6

What is the formula for (Ar)? (1)

Answer 6

Ar = (%/100 x Isotope) + (%/100 x Isoptope)

Question 7

When given the Ar, how to do you find percentage of the Isotopes? (1)

Answer 7

(x/100 x Isotope) + (100-x/100 x Isotope) = Ar

Question 8

What is an ion?
What is a cation?
What is an anion?
(3)

Answer 8

• An ion gains or loses electrons
• A cation is when the ion is positively charged
• An anion is when the ion is negatively charged

Question 9

Standard mass?

Answer 9

Carbon ( 12 units)
Therefore Hydrogen (1) = 1/12 units
Ar (H) = 1 unit

Question 10

What is an orbital?

Answer 10

An orbital is a three dimension region around the nucleus where there is a high probability of finding an electron with a certain amount on energy.

Question 11

S- orbital?
P- orbital?
(2)

Answer 11

• S orbital is spherical
• S orbital has less energy
• 1 orbital
• P orbital is tear drop shaped
• P orbital has more energy
• P orbital has 3 orbitals

Question 12

What can an orbital accommodate? (1)

Answer 12

An orbital can accommodate 2 electrons with opposite spin.

Question 13

Valence electron? (1)

Answer 13

Electrons that occupy that occupy the outer most energy level

Question 14

Why are the valence electrons important? (2)

Answer 14

• First to interact with other electrons

- Electrons involved in bonding

Question 15

What are the Core electrons? (2)

Answer 15

• Electrons that occupy the inner energy levels

- Shield the valence electrons from the nuclei’s attraction

Question 16

Energy level=
Valence electrons=
(2)

Answer 16

• e.l = period

- v.e = group A

Question 17

Atomic Diameter? (2)

Answer 17

• How far the electrons are positioned from the centre

- no definite limit

Question 18

Radius of an atom? (2)

Answer 18

• Found by measuring the distance between the 2 nuclei of the touching atoms
• Then halving the distance

Question 19

Why does the atom size get bigger when there are more electron shells? (2)

Answer 19

• more energy levels

= more shielding

Question 20

What is the Shielding Affect? (1)

Answer 20

• When the inner electrons are shielding the outer electrons

Question 21

More Radius = (1)

Answer 21

More shielding

Question 22

When does the atom size get smaller? (2)

Answer 22

• When the valence electrons fill up the outer energy levels
• more energy = attraction
  = smaller

Question 23

What is Ionisation Energy? (2)

Answer 23

The minimum amount of energy required to remove an electron from an atom in the gas phase

Question 24

First and second Ionisation energy? (2)

Answer 24

Removing the first electron

Removing the second electron

Question 25

Why are Valence electrons generally easy to remove? (1)

Answer 25

Least attracted to the nucleus

Question 26

2 things affecting Ionisation energy. (2)

Answer 26

• Atomic radius (if small, higher Ionisation energy (if valence electrons fill up the outer energy levels))
• Charge ( higher positive charge- harder to pull away

Question 27

When does Ionisation energy increase?
When does Ionisation energy decrease?
(2)

Answer 27

• increase = as move across period

- decrease = as move down a group

Question 28

Protons and Neutrons are collectively known as? (1)

Answer 28

Nucleons