The Periodic Table
How many protons does Lithium (Li) have?
3
How many protons are in Neon?
10
How many atoms are in H₂?
two H (Hydrogen) atoms
In H₂O, which element does the “2” affect?
Hydrogen
What makes up an element?
One type of atom
Which group contains the Noble Gases?
Group 18
What does the Bohr Model demonstrate?
Electrons orbiting around the nucleus
Count the atoms in CO₂.
C = 1
O = 2
Total = 3
In Ca(OH)₂, which atoms does the subscript “2” apply to?
Hydrogen and Oxygen
What makes up molecules?
Different amounts of molecules
What is the symbol for the element in Group 1, Period 5?
Rb
Draw (or describe) the electron arrangement for Sodium. (Think how many electrons are on each ring)
2, 8, 1
Count the atoms in H₂SO₄
H = 2
S = 1
O = 4
Total = 7
In 3Na(SO₄), which element(s) does the “3” apply to?
All elements in the formula
Which group of elements is the most reactive?
Alkali Metals - Group 1
How many electrons does Oxygen have?
8
How many neutrons does Aluminum usually have?
14
Count the atoms in 2Mg(OH)₂
Mg = 2
O = 4
H = 4
Total = 10
What does a coefficient do in a chemical formula?
Multiplies the whole compound
Which group contains elements that are not very reactive and stable?
Noble Gases
What is a metalloid?
Elements with properties of both metals and nonmetals
What element has 2 energy levels and 9 electrons?
Fluorine
Count the atoms in Al₂(SO₄)₃
Al = 2
S = 3
O = 12
Total = 17
Compare subscript vs. coefficient.
Subscript applies to one element; coefficient applies to the whole compound
What is the difference between a compound and a molecule?
A molecule is two or more atoms chemically bonded, while a compound is a molecule made of two or more different elements.