Atoms, ions and compounds

Question 1

The identity of an element

Answer 1

Every atom of an element contains the same amount of protons. The periodic table is in order of atomic number( proton number)

Question 2

What is an isotope?

Answer 2

Atoms of an element which have the same number of protons but different number of neutrons

Question 3

How is the percentage abundances of isotopes in a sample found?

Answer 3

using a mass spectrometer

Question 4

What are positive and negative ions also known as?

Answer 4

cations(positive) and anions(negative)

Question 5

What is the explanation of the term relative isotopic mass?

Answer 5

the mass compared with 1/12th mass of carbon-12

Question 6

what is the explanation of the term relative atomic mass?

Answer 6

the weighted MEAN mass compared with 1/12th of carbon-12

Question 7

how do you calculate the relative atomic mass?

Answer 7

(relative isotopic mass1 x percentage abundance of isotope 1) + (relative isotopic mass2 x abundance of relative isotope 2) all divided by 100

Question 8

How does the mass spectrometer work?

Answer 8

1) sample is placed inside and is vapourised. Then ionised to form positive ions.
2) the ions are accelerated. Heavier ions move more slowly and are more difficult to deflect, so the ions of each isotope are separated.
3) the ions are detected on a mass spectrum as a mass to charge ratio. Each ion reaching the detector adds to the signal, so the greater the abundance, the greater the signal.

Question 9

what is the relative mass of an electron?

Answer 9

1/2000

Question 10

what is the formula of the ferrate ion? (1mark)

Answer 10

FeO4 2-