Elements, Atoms, Molecules & Compounds
Which statement below is true about water? a) all of the above b) water is a compound c) water is made up of H2O molecules d) there are 2 different elements in a water molecule
a) all of the above
How many total atoms are in a reactant with this chemical formula? 3H₂O
9
Which of the following chemical formulas has 2 molecules? 2NaCl 3CO2 03 H2O2
2NaCl
Which of the following chemical formulas has 3 molecules? 2NaCl 3CO2 03 H2O2
3CO2
Which of the following chemical formulas has the most oxygen atoms? 2NaCl 3CO2 03 H2O2
3CO2
Which of the following chemical formulas has the most total atoms? 2NaCl 3CO2 03 H2O2
3CO2
Molecule
A group of 2 or more atoms bonded together.
Compound
A molecule made up of two or more different elements.
Element
A pure substance made of only one kind of atom
Chemical Equation
A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products
Which statement below is true? A) A molecule is 2 or more atoms that have chemically combined B) All molecules are also compounds C) Atoms are made of molecules D) Elements are made of compounds
A) A molecule is 2 or more atoms that have chemically combined
Which of the following is true? A) Atoms combining to make molecules is a chemical change B) Atoms combining to make molecules is a physical change C) Atoms do not combine to make molecules D) One atom can be a molecule
A) Atoms combining to make molecules is a chemical change
Which of the following is the symbol for carbon? C Ca Cl Cr
C
Which of the following is the symbol for calcium? C Ca Cl Cr
Ca
Which of the following is NOT one of the steps for balancing a chemical equation? A) Make a list of all the elements on each side of the equation B) Count how many of each element you have C) Check to see if the equation is balanced D) Change the subscripts to make the equation balanced.
D) Change the subscripts to make the equation balanced.
Which of the following chemical formulas has 2 hydrogen atoms? 2NaCl 3CO2 03 H2O2
H2O2
Which of the following chemical formulas has 3 oxygen atoms? 2NaCl 3CO2 03 H2O2
O3
Which of the following chemical formulas has the least total atoms? 2NaCl 3CO2 03 H2O2
O3
Law of Conservation of Matter
States that matter cannot be created or destroyed during a chemical reaction.
Coefficient
The larger number at the front of the chemical formula. This tells us how many molecules we have.
Subscript
The small number in a chemical formula. It tells us the number of atoms of each element in a molecule.
Atom
The smallest part of an element/matter. The building blocks of matter.
What does the arrow ( ---->) in a chemical equation mean?
Yields