2.1.1 atomic structure and isotopes

Question 1

what is the relative mass of an electron?

Answer 1

1/1836

Question 2

what is an isotope?

Answer 2

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

Question 3

how do different isotopes effect chemical reactions?

Answer 3

no effect - different isotopes have the same number of electrons so therefore react in same way

Question 4

what are cations?

Answer 4

positive ions - atoms with fewer electrons than protons

Question 5

what are anions?

Answer 5

negative ions - atoms with more electrons than protons

Question 6

what isotope is used as the standard isotope for atomic mass measurements?

Answer 6

carbon-12

Question 7

what is the unit for atomic mass?

Answer 7

u

Question 8

what is the approximate mass of a proton or neutron?

Answer 8

1 u

Question 9

what is relative isotopic mass?

Answer 9

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

Question 10

what is relative atomic mass?

Answer 10

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

Question 11

how do you determine relative atomic mass?

Answer 11

the percentage abundances of the isotopes in a sample of an element are found experimentally using a mass spectrometer

Question 12

calculating relative atomic mass

Answer 12

( % x i1 + % x i2 ) /100