atomic structure & isotopes

Question 1

What is an atom

Answer 1

-An atom is the basic unit that makes up all matter

Question 2

what is the relative charge and relative mass of sub-atomic particles

Answer 2

-Electron -1, 0.0005
-Proton +1, 1
-Neutron 0, 1

Question 3

What is the order of people who discovered models of an atom

Answer 3

-Dalton (1800)
- Thompson (1897)
-Rutherford & Geiger (1909)
-Bohr (1913)
-Rutherford (1918)
-Chadwick (1932)

Question 4

What did Dalton discover

Answer 4

-John Dalton created the first atomic model, the billiard ball model. In this model he described that:

-Atoms are tiny particles that make up an element

-Atoms that make up a given element are all the same

-Therefore atoms that make up one element are different from the atoms that make up another element

-Atoms cannot be split any further

Question 5

What did Thompson discover

Answer 5

-Thomson proved that atoms can be broken down further into smaller pieces because he discovered the electron
-He discovered electrons from doing work with cathode rays
-This led to Thomson developing
the plum pudding model where
he said an atom is made up of
negative electrons moving
around a sea of positive charge

Question 6

What did Rutherford and Geiger discover

Answer 6

-Through the alpha scattering experiment , they discovered that most of the atoms mass is concentrated in the centre : this lead to discovery of the nucleus

Question 7

what did Bohr discover

Answer 7

-Bohr discovered that electrons orbit the nucleus in definite orbits called electron shells at specific distances from the nucleus and electrons remain in these fixed orbits because energy is needed to move

Question 8

What did rutherford discover

Answer 8

-The proton

Question 9

What did chadwick discover

Answer 9

-the neutron

Question 10

What is an isotope

Answer 10

-Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons

Question 11

Why do isotopes of the same element react the same

Answer 11

-They have the same electronic configuration

Question 12

what is relative atomic mass AR

Answer 12

-The average mass of an element compared with 1/12th the mass of a carbon 12 atom.

Question 13

How to calculate average atomic mass

Answer 13

(mass of I1x abundance of I1) + (mass of I2+ abundance of I2) /total abundance