Chapter 3&4- Atomic Structure

Question 1

What is an element?

Answer 1

An element is a substance that cannot be broken down into similar substances by chemical means

Question 2

What is a triad?

Answer 2

A group of 3 elements that have similar chemical properties in which the middle is the average atomic weight of the others

Question 3

What are Newlands octaves?

Answer 3

Arrangements of elements in which the first and eighth element have similar properties

Question 4

What does Mendeleev’s Periodic Law state?

Answer 4

When elements are arranged in order of increasing atomic {weight}, then properties of elements occur periodically.

Question 5

What is the Modern Periodic Law?

Answer 5

When elements are arranged in order of increasing atomic {number}, properties of elements recur periodically

Question 6

What are the 3 key differences between Mendeleev’s Periodic Table and the Modern Periodic Table?

Answer 6

Question 7

Define the “Atomic number” of an atom

Answer 7

Number of protons in the nucleus of an atom

Question 8

Define the “Mass number” of an atom

Answer 8

Number of protons + neutrons in the nucleus of an atom

Question 9

Define the term “isotope”

Answer 9

Atoms of the same element which have a different mass number due to different quantities of neutrons

Question 10

Define “Relative Atomic Mass”

Answer 10

The average mass numbers of the isotopes of an element.

Question 11

How does a mass spectrometer work? (5 stages)

Answer 11

1. Vaporisation
2. Ionisation
3. Acceleration
4. Separation
5. Detection

Question 12

What is an energy level?

Answer 12

An energy level is the fixed energy value that an electron in an atom may have

Question 13

What is the ground state of an atom?

Answer 13

The ground state of an atom is one in which the electrons occupy the lowest available energy level

Question 14

What is the excited state of an atom?

Answer 14

The excited state of an atom is one in which electrons occupy higher energy levels than those available in the ground state

Question 15

What is the principal of mass spectrometry?

Answer 15

Charged particles moving in a magnetic field are deflected to different extents according to their masses and are separated accordingly

Question 16

What is an orbital?

Answer 16

An orbital is a region in space within which there is a high probability of finding an electron

Question 17

What is a sublevel?

Answer 17

A sublevel is a subdivision of a main energy level and consists of one or more orbitals of the same energy

Question 18

What does an electronic configuration do?

Answer 18

Show the arrangement of electrons in an atom of an element

Question 19

What are the names of the first 10 sublevels?
and how many electrons can they hold each?

Answer 19

Question 20

What are the exceptions to the rules of electronic configuration?

Answer 20

Chromium which ends in 4s1, 3d5 (rather than 4s2 3d4)
Cobalt which ends in 4s1, 3d10 (rather than 4s2 3d9)

Question 21

Define the Aufbau Principal

Answer 21

Electrons always occupy the lowest available energy level in its ground state

Question 22

What is Hund’s rule of maximum multiplicity?

Answer 22

When two or more orbitals of equal energy are available, the electrons occupy them singly before filling them in pairs.

Question 23

What is Pauli’s Exclusion Principle?

Answer 23

No more than 2 electrons may occupy the same orbital and they must have opposite spin

Question 24

What does Heisenberg’s Uncertainty Principal state?

Answer 24

It is impossible to measure at the same time both the velocity and the position of an electron