Elements And Chemical Equations Flashcards
(24 cards)
What is an element?
A substance made of only one type of atom.
What is a chemical symbol?
A one- or two-letter code representing an element.
What is a compound?
A substance made of two or more different elements chemically bonded together.
What is a chemical formula?
A way of showing the elements in a compound and their ratios.
What does H₂O represent?
Water – 2 hydrogen atoms and 1 oxygen atom.
What does CO₂ represent?
Carbon dioxide – 1 carbon atom and 2 oxygen atoms.
What is a chemical equation?
A representation of a chemical reaction using symbols and formulas.
What are reactants?
The substances you start with in a chemical reaction.
What are products?
The new substances formed in a chemical reaction.
Where are reactants written in a chemical equation?
On the left side of the arrow.
Where are products written in a chemical equation?
On the right side of the arrow.
What does the arrow in a chemical equation mean?
‘Produces’ or ‘forms’ – shows the direction of the reaction.
What is a balanced chemical equation?
An equation with equal numbers of each type of atom on both sides.
Why must chemical equations be balanced?
To obey the law of conservation of mass.
What does (s) mean in a chemical equation?
Solid.
What does (l) mean in a chemical equation?
Liquid.
What does (g) mean in a chemical equation?
Gas.
What does (aq) mean in a chemical equation?
Aqueous – dissolved in water.
What is a state symbol?
A symbol that shows the physical state of a substance in a chemical equation.
What is the formula for magnesium oxide?
MgO
What is the formula for sodium chloride?
NaCl
What is the word equation for the reaction of hydrogen and oxygen?
Hydrogen + Oxygen → Water
What is the balanced symbol equation for hydrogen and oxygen?
2H₂ + O₂ → 2H₂O
What is the word equation for iron reacting with oxygen?
Iron + Oxygen → Iron oxide
