Which subatomic particle has a negative charge?
Electron
What is a molecule?
Two or more atoms bonded together
How many total atoms are in CO₂?
3 atoms.
How many bonds does hydrogen usually form?
1 bond.
What does the coefficient in 4NH₃ tell you?
There are 4 NH₃ molecules, so you multiply each atom count by 4.
What does an element's atomic number tell you?
The number of protons.
What does the small subscript in H₂O tell you?
There are 2 hydrogen atoms.
How many hydrogen atoms are in 5H₂O?
10 hydrogen atoms.
How many bonds does oxygen usually form?
2 bonds.
How many total atoms are in 3CH₄?
15 atoms.
A neutral atom has 16 protons. How many electrons does it have?
16 electrons.
What does a line between atoms represent in a 2-D structure?
A chemical bond.
How many oxygen atoms are in 2CaCO₃?
6 oxygen atoms.
What are two lines between the same two atoms called?
A double bond.
Count every type of atom in 4Ca(OH)₂.
Ca = 4, O = 8, H = 8.
An atom has 8 protons and 9 neutrons. How many particles are in its nucleus?
17 particles.
Explain the difference between a chemical formula and a 2-D structure.
A formula shows the types and numbers of atoms. A 2-D structure shows how the atoms are connected.
How many oxygen atoms are in 3Mg(NO₃)₂?
18 oxygen atoms.
Draw a correct 2-D structure for NH₃.
Nitrogen in the center with three single bonds to hydrogen atoms.
How many total atoms are in 2Fe₂(CO₃)₃?
28 atoms.
An atom has 13 protons, 14 neutrons, and 13 electrons. What is its atomic number, and is it neutral?
Atomic number 13; yes, it is neutral.
Why do we use 2D structures?
To show us the number of bonds in a molecule
Count every type of atom in 2Al₂(SO₄)₃.
Al = 4, S = 6, O = 24.
Draw a correct 2-D structure for C₃H₈.
Three carbon atoms connected in a chain, with eight hydrogen atoms completing the bonds. Each end carbon has 3 hydrogen atoms, and the middle carbon has 2.
Count every type of atom in 3Al₂(SO₃)₃.
Al = 6, S = 9, O = 27.