atomic structure

Question 1

what is a negative ion?

Answer 1

gain e- to gain a full outer shell of e- and enable a more stable ionic compound

Question 2

what is a positive ion?

Answer 2

have lost e- to gain a full outer shell of e- and enable a more stable ionic compound

Question 3

what is an isotope?

Answer 3

elements have the same number of protons but a different number of neutrons

Question 4

what did dalton do?

Answer 4

1803) atoms are spherical and each element has a different spherical shape

Question 5

what did JJ Thompson do?

Answer 5

1897) discovered the e-/plum pudding model

Question 6

what did Rutherford do?

Answer 6

1909) discovered the nucleus- small and positively charged

Question 7

what were the findings of Rutherford alpha gold experiment?

Answer 7

98%- most went straight through the gold foil, shows the atom was mostly empty space
~2%- went straight through but were deflected, shows the nucleus has a positive charge
1/1800- deflected back, nucleus was small and dense

Question 8

what did Bohr do?

Answer 8

1913- proposed e- were in fixed energy shells

Question 9

what was Bohr’s experimental proof?

Answer 9

when electromagnetic radiation is absorbed, electrons move between shells. they emit this radiation when electrons move down to lower energy shells

Question 10

explain electrospray ionisation

Answer 10

the sample is vaporised.
the sample is pushed through a needle at a high voltage and high pressure, causing the gain of a H+.
the positive ion is passed through an electric field (particles with a lower mass to charge ratio will accelerate faster)
particles travel at a constant speed
ions are detected as electrical current is made when the ions hit the plate.