6 Main Stabes Of Discprering Atoms C1

Question 1

First suggestion of atoms

Answer 1

Democritus suggested atoms make up all material

Question 2

Stage 2 John dalton

Answer 2

John Dalton 1804
suggested all matter was made of atoms

Question 3

Stage 3 JJThompson, early 20thC

Answer 3

showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom

Question 4

Rutherfords suggestion on the structure of the atom stage 4

Answer 4

Ernest Rutherford found that the atom is mostly empty space, with nearly all of its mass concentrated in a tiny central nucleus. The nucleus is positively charged and surrounded at a great distance by the negatively charged electrons.

Question 5

Bohrs discovery

Answer 5

Bohr discovered electron shells

Question 6

Chadwick discovery

Answer 6

Chadwick discovered neutrons

Question 7

Information about mendeleevs discovery of the atom

Answer 7

He published his first periodic table of the elements in 1869. In it, he arranged the elements in order of increasing atomic weights. He also took into account the
properties
of the elements and their
compounds
. This meant that his table:
had gaps in it
showed elements with similar chemical properties lined up in groups

Question 8

Information about Mendeleevs gaps

Answer 8

Mendeleev left gaps in his table for elements not known at the time. By looking at the properties of the elements next to a gap, he could also predict the properties of these undiscovered elements.