Chapter 4: Atomic Structure Flashcards
1
Q
How do electrons change their orbits?
A
By absorbing or emitting electromagnetic radiation
2
Q
What determines an atom’s element?
A
Number of protons
3
Q
What is the atomic number?
A
The number of protons
4
Q
What is the mass number?
A
The total number of particles in the nucleus
5
Q
What is an isotope?
A
A version of an atom with a different number of neutrons
6
Q
What is the plum pudding model of the atom?
A
Atoms were made up of electrons inside a field of positive charge, like a plum pudding
7
Q
Who showed that electrons are negatively charged?
A
J J Thompson when he discovered that electrons were emitted from the surface of hot metals
8
Q
How was the nuclear model of the atom discovered?
A
They directed a beam of alpha particles at a thin sheet of gold foil [UNFINISHED]
