2.1 Atomic Structure and Isotopes and 2.2 Relative mass

Question 1

What is the relative mass of an electron?

Answer 1

1/1836

Question 2

What is the relative charge of a proton?

Answer 2

1

Question 3

What is the relative charge of a neutron?

Answer 3

1

Question 4

What is the relative bathe of an electron

Answer 4

1-

Question 5

What is the relative charge of a proton?

Answer 5

1+

Question 6

What is the relative charge of a neutron?

Answer 6

0

Question 7

What is he overall charge of an atom?

Answer 7

0

Question 8

What is the role of the neutrons?

Answer 8

The glue that holds the nucleus together despite the electrostatic forces of attraction

Question 9

What is the relationship between size of the nucleus and the number of protons in the nucleus?

Answer 9

As the nucleus gets larger, more and more neutrons are needed

Question 10

What is the atomic number?

Answer 10

The number of protons in the nucleus

Question 11

What is an isotope?

Answer 11

An isotope if an element is an atom that has the same number of protons as that element (atomic number) but different number of neutrons and different masses

Question 12

What does the A stand for in chemical notation?

Answer 12

Mass number

Question 13

What does the Z stand for in chemical notation?

Answer 13

Atomic number

Question 14

How are isotopes chemically and physically different?

Answer 14

Different isotope of an element react in the same way
- because they have the same number of electrons and neutrons have no effect on reactions of an element

Different isotopes have small differences in physical properties
- higher-mass isotopes of an element have higher melting point, boiling point and density

Question 15

What are cations?

Answer 15

Positive ions

- have fewer electrons than protons

Question 16

What are anions?

Answer 16

Negative ion

-Have more electrons than protons

Question 17

What is relative isotopic mass?

Answer 17

The mass of an isotope relative to 1/12th of the mass of carbon-12

Question 18

What is relative mass?

Answer 18

The weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12

Question 19

What does the weighted mean mass take account of?

Answer 19

The percentage abundance of each isotope

The relative mass of each isotope

Question 20

How does mass spectrometry work?

Answer 20

1. A sample is placed in the mass spectrometer
2. The sample is vaporised and then ionised to form positive ions
3. The ions are accelerated.Heavier ions move more slowly and are more difficult to deflect than lighter ions, so the ions if each isotope are separated
4. The ions are detected on a mass spectrum as a mass to charge ratio (m/z). Each ion teaching the detector adds to the signal, so the greater the abundance, the larger the signal

Question 21

How do you work out relative atomic mass?

Answer 21

(Percentage of isotope1 x atomic mass of isotope1 + Percentage of isotope1 x atomic mass of isotope1) all divided by 100