Atomic Structure,isotopes, Compounds, Formula And Equations

Question 1

What is stated in daltons atomic theory

Answer 1

Atoms are tiny particles made of elements
Atoms can’t be divided
All atoms in an element are the same
Atoms of one element are different to those of other element

Question 2

What did Thompson discover about electrons

Answer 2

They have a negative charge
They can be deflected by a magnet and electric field
They have very small mass

Question 3

Explain the plum pudding model

Answer 3

Atoms are made up of electrons moving around in a sea of positive charge

Question 4

What were Rutherfords proposal after the gold leaf experiment

Answer 4

Most of the mass and positive charge of the atom are in the nucleus
Electrons orbit the nucleus
Most of the volume is the space between the nucleus and the electrons
Overall positive and negative charges must balance

Question 5

Explain the current model of the atom

Answer 5

Protons and neutrons are found in the nucleus
Electrons orbit in shells
Nucleus is tiny compared to the total volume of atom
Most of atoms mass in the nucleus
Most of the atom is empty space between the nucleus and the electrons

Question 6

What does the atomic number tell about an element

Answer 6

Atomic number = number of protons in an atom

Question 7

Which letter is used to represent the atomic number of an atom

Answer 7

Z

Question 8

Which letter represents the mass number

Answer 8

A

Question 9

How is mass number calculated

Answer 9

Mass number = number of protons + number of neutrons

Question 10

How to calculate number of neutrons

Answer 10

Number of neutrons = mass number - atomic number

Question 11

Define isotope

Answer 11

Atoms of the same element with different number of neutrons

Question 12

Why does different isotopes of the same element react in the same way

Answer 12

Neutrons have no impact on the chemical reactivity
Reactions involve electrons, have the same number of electrons in the same arrangement

Question 13

What are ions

Answer 13

Charged particles that is formed when an atom loses or gains electrons

Question 14

Define relative atomic mass

Answer 14

The weighted mean mass of an atom of an element compared with one twelfth of the mass of an atom of carbon-12

Question 15

What is the unit of relative atomic mass

Answer 15

No units

Question 16

Define relative isotopic mass

Answer 16

The mass of an atom of an isotope compared with one twelfth of the mass of an atom of carbon-12

Question 17

The relative isotopic mass is same as which number

Answer 17

Mass number

Question 18

What two assumptions are made when calculating mass number

Answer 18

1- contribution of the electron is neglected
2- mass of both proton and neutron is taken as 1.0 u

Question 19

How to calculate the relative molecular mass and relative formula mass

Answer 19

Both can be calculated by adding the relative atomic masses of each of the atom making up the molecule or the formula

Question 20

What are the uses of mass spectrometry

Answer 20

• identify unknown compounds
  -find relative abundance of each isotope of an element
  -determine structural information

Question 21

How does a mass spectrometer work

Answer 21

The sample is made into positive ions
They pass through the apparatus and are separated according to mass to charge ratio
A computer analyses the data and produces mass spectrum

Question 22

How is the group number related to the number of electrons

Answer 22

Group number = number of electrons in the outer shell

Question 23

Does the group number indicate horizontal or vertical column in the periodic

Answer 23

Vertical column

Question 24

Do metals normally gain or lose electrons

Answer 24

Lose electrons

Question 25

What 4 elements don’t tend to form ions

Answer 25

Beilyium, boron, carbon silicon

Requires a lot of energy to transfer outer shell electrons

Question 26

What are molecular ions

Answer 26

Covalently bonded atoms that lose or gain electrons

Question 27

What is the charge of an ammonium ion

Answer 27

Nh4+1

Question 28

What is the charge of a carbonate ion

Answer 28

Co3 2-

Question 29

What is empirical formula

Answer 29

Simplest whole number ratio of atoms of each element present in a compound

Question 30

How to calculate empirical formula

Answer 30

Divide the amount of each element by its mass
Divide the answers by smallest value obtained
If there is a decimal, divide by suitable number to make it whole