Atomic Sturcture
What is the charge of an electron?
Negative
Who developed the Periodic Table?
Dmitri Mendeleev
Elements are arranged in order of increasing what?
Atomic number
How many electrons fit in the first shell?
2
Elements in the same group have the same number of what?
Valence electrons
What particle has no charge?
Neutron
Who proposed the "Plum Pudding" model of the atom?
J.J. Thomson
What are the three classifications of elements?
Metals, non-metals, metalloids
What is the electron arrangement for lithium (3 electrons)?
2, 1
What does the period (row) number tell us?
Number of electron shells
What does the atomic number tell us?
Number of protons and electrons
Explain the Plum Pudding Model.
The atom was thought to be a positively charged sphere with negatively charged electrons scattered throughout it.
What is a metalloid?
An element with properties of both metals and non-metals
What is the electron arrangement for magnesium (12 electrons)?
2,8,2
How many valence electrons does chlorine have?
7
Which two particles make up most of an atom's mass?
Protons and neutrons
Who proposed the Nuclear Model after discovering the nucleus?
Ernest Rutherford
Give one example of a metal
Na, Mg, Fe, Al, etc
What is the electron arrangement for chlorine (17 electrons)?
2, 8, 7
Why are noble gases unreactive?
They have a full outer electron shell
An atom has 12 protons and 12 neutrons. What is its mass number?
24
Explain how Bohr's model was different from Rutherford's model.
Rutherford said electrons orbit the nucleus. Bohr improved this model by suggesting that electrons can only exist in specific shells (energy levels) around the nucleus.
What classification is silicon?
Metalloid
An atom has the electron arrangement 2,8,8,2. What element is it?
Calcium
An atom has the electron arrangement 2,8,1. Is it reactive or unreactive?
Reactive