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WorksheetsCounting Atoms
Total questions: 28
Worksheet time: 56mins
The building blocks of all matter is:
cells
elements
atoms
mass
Which of the following are found on the Periodic Table?
Elements
Compounds
Molecules
Atoms
How many electrons are needed to make the element in the picture neutral?
4
16
8
32
A sodium atom has 11 protons and 10 electrons. What is its charge?
+11
-1
+1
-10
What does the 4 represent?
period number
atomic number
element name
chemical symbol
Which of the following is a molecule but not a compound?
O
H2
H2O
C6H12O6
What does the number of protons in an atom tell us?
The number of electrons
The atomic number
The atomic mass
The number of neutrons
If an atom has 6 protons, 7 neutrons, and 6 electrons, what is its charge?
Positive
Negative
Neutral
Not enough information
The positively charged part of an atom that is found in the nucleus is the...
proton
neutron
electron
element
What part of an atom has no charge and is found in the nucleus?
proton
neutron
electron
element
How many Hydrogen are in 4H2O?
8
6
4
2
What is the product in: 2H2 + O2 --> 2H2O?
H2 + O2
O2
H2O
-->
How many elements are in C6H12O6?
1
3
6
24
How many total atoms are in H2SO4?
3
5
6
7
A subscript is the small number below a(n) __ that tells the number of __ of the element.
element symbol, atoms
atom, element symbol
subscript, protons
compound, elements
What is a coefficient?
the small number on the right of the chemical symbol
the large number to the left of a formula
the numbers inside of the parentheses
the small number to the left of the chemical symbol
The law of conservation of mass states that:
chemical reactions change matter.
in chemical reactions, the identity of reactants and products is conserved
atoms are neither created nor destroyed in chemical reactions
A chemical equation must be balanced
The coefficient in 3H2O is:
6
5
3
2
What is the total number of atoms present in 5Na3PO4?
55
40
8
5
What is the right side of a chemical equation called? 2H2 + O2 --> 2H2O
Product
Rectant
Equation
Equals
What is the little number after an element in a chemical equation called? H2
Element
Atom
Coefficient
Subscript
Which of the following equations are correctly balanced?
12CO2 + H2O --> C6H12O6 + O2
CO2 + H2O --> 3C6H12O6 + O2
CO2 + 9H2O --> C6H12O6 + O2
6CO2 + 6H2O --> C6H12O6 + 6O2
How many HCl molecules do you need to balance this equation? Mg + __HCl --> MgCl2 + H2
1
2
3
4
How many NaOH molecules do you need to balance the following equation? 2Na + 2H2O -->__NaOH + H2
1
2
3
4
How many H2O molecules are needed to balance the following equation? Ca + __H2O --> Ca(OH)2 + H2
1
2
3
4
How many CO2 molecules are needed to balance the following equation? 3CO + Fe2O3 --> 2Fe + __CO2
1
2
3
4
How can the following equation be balanced? _CF4 + _Br2 --> _CBr4 + _F2
2, 1, 2, 1
1, 2, 1, 2
1, 2, 2, 1
2, 2, 2, 1
Balance the following equation: _SnO2 + _H2 --> _Sn + _H2O
1, 1, 2, 1
1, 2, 1, 2
1, 2, 1, 1
1, 2, 2, 1
