ATOMS, IONS AND COMPOUNDS

Question 1

Which 2 subatomic particles are found in a nucleus?

Answer 1

Protons

Neutrons

Question 2

Protons and neutrons have the same…

Answer 2

Mass

Question 3

What is the relative mass of an electron?

Answer 3

1/1836 th the mass of a proton

Question 4

What charge does a proton have?

Answer 4

Positive charge 1+

Question 5

What charge does an electron have?

Answer 5

Negative charge 1-

Question 6

What charge does a neutron have?

Answer 6

No charge, it is neutral

Question 7

Where is most of the mass of an atom found?

Answer 7

In the nucleus

Question 8

Atoms contain the same number of….

Answer 8

Protons and electrons

Question 9

What is the overall charge of an atom?

Answer 9

Zero

The charges cancel out - an atom is neutral

Question 10

What is an Isotope?

Answer 10

Isotopes are atoms of the same element with different numbers of neutrons and different masses

They still have the same number of electrons

Question 11

Does the number of neutrons have an effect in the reactions of an element?

Answer 11

No, therefore different isotopes of an element react in the same way

Question 12

What is the name of “Heavy water”

Answer 12

Deuterium

Question 13

What is special about Deuterium compared to normal water?

Answer 13

Greater density
Higher melting point and boiling point (by a little)

Water would freeze at a higher temp (if deuterium)

Question 14

What is an ion?

Answer 14

A charged atom

Different numbers of electrons
So there is an overall charge

Question 15

What are cations?

Answer 15

Positive ions

More protons than electrons
Overall positive charge

Question 16

What are anions?

Answer 16

Negative ions

More electrons than protons
Overall negative charge

Question 17

What is the difference between ions and atoms?

Answer 17

Same number of protons

But different number of electrons

Question 18

What is Relative Isotopic Mass?

Answer 18

Relative Isotopic mass is the mass of an isotope relative to 1/12th of the mass of an atom of carbon 12

Question 19

Mass number is…

Answer 19

MASSive (the bigger number)

Sum of the protons and neutrons

Question 20

What is Relative Atomic Mass?

Answer 20

Relative atomic mass, Ar, is the weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon 12

Question 21

How are the percentage abundances of isotopes found?

Answer 21

Using a mass spectrometer

Question 22

Describe how a mass spectrometer is used to find the percentage abundances of isotopes

Answer 22

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 ones, so the ions of each isotope are separated
4. The ions are detected on a mass spectrum as a m/z

Each ion reaching the detector adds to the signal
So the greater the abundance
The larger the signal

Question 23

How do you determine the m/z ratio of an element?

Answer 23

Relative mass of ion / Relative charge of ion

Question 24

What does the M in m/z stand for?

Answer 24

Mass

Question 25

What does the Z in m/z stand for?

Answer 25

Charge

Question 26

What does m/z stand for?

Answer 26

Mass-to-charge ratio

Question 27

Which atoms lose electrons to form cations and gain a full outer shell?

Answer 27

Metals

Question 28

Which atoms gain electrons to form anions and gain a full outer shell?

Answer 28

Non-metals

Question 29

Formulae for Ammonium ion?

Answer 29

NH4+

Question 30

Formulae for Hydroxide ion?

Answer 30

OH-

Question 31

Formulae for Carbonate ion?

Answer 31

CO3 ^2-

Question 32

Formulae for Nitrate ion?

Answer 32

NO3 -

Question 33

Formulae for Sulfate ion?

Answer 33

SO4 ^2-

Question 34

Formulae for Nitrite ion?

Answer 34

NO2 -

Question 35

Formulae for Sulfite ion?

Answer 35

SO3 2-

Question 36

List the diatomic molecules

Answer 36

H2
N2
O2
F2
Cl2
Br2