Model Of The Atom 1.1.3 Flashcards
Who devised the plum pudding model in 1897?
J.J Thomson.
What is the plum pudding model?
A positively charged ball with electrons inside.
Who devised the nuclear model in 1909?
Ernest Rutherford.
What is the nuclear model?
The mass of the atom is concentrated in a nucleus.
The nucleus contains protons.
Who devised the modern model?
Niels Bohr.
What is the modern model?
Electrons orbit a positively charged nucleus at fixed distances.
Who discovered the neutron in 1932?
James Chadwick.
What charge does a proton have?
Positive, +1.
What is the atomic number a measure of?
Number of protons.
An element is defined by what?
It’s proton/atomic number.
What charge does an electron have?
Negative, -1.
The number of electrons is equivalent to…
The number of protons.
What charge does a neutron have?
Neutral, no net charge.
What is the mass of a proton and an neutron?
1.
What is the mass of an electron?
0.0005 (0).
