Elements, Molecules and Compounds
The smallest unit of matter which has properties of a chemical element.
What is an atom?
These are the ingredients of a reaction; they are on the left side of the arrow.
What are reactants?
The subatomic particles (the parts of an atom.)
What are protons, neutrons, and electrons.
Matter can neither be _____________ nor ______________.
What is created/made, destroyed/lost?
This tells the number of protons in an atom.
What is the atomic number?
Two or more atoms bonded together form this.
What is a molecule?
A process that involves the rearrangement of atoms to form new substances.
What is a chemical reaction? (law of conservation of matter/mass)
The location where most mass is found in an atom
What is the nucleus?
You burn a log and the ashes weigh less than the log. Does this violate the Law of Conservation of Matter? Why or why not?
What is no, because some matter turned into gases that escaped into the air?
This substance releases hydrogen ions (H⁺) in water.
What is an acid?
Water (H₂O) is an example of this kind of substance, made of more than one type of element chemically combined.
What is a compound?
The rusting of iron is an example of this kind of change.
What is a chemical change (or oxidation)?
The charge and location of an electron
What is negative and found in electron clouds/shells?
The grams of product in a chemical reaction, if you start with 20 grams of reactants.
What is 20 grams (because matter is conserved)?
This is a combination of substances that are NOT chemically bonded together.
What is a mixture?
How we can categorize, O₂, which represents two oxygen atoms bonded together.
What is both an element and a molecule?
This is the formation of a solid from two liquids mixing, often seen as a cloudy substance.
What is a precipitate?
The charge and location of a neutron.
What is no charge (neutral) and located in the nucleus?
List at least 3 indicators of a chemical change.
What are unexpected color changes, gas is produced (smell or bubbles or fizz), a solid is formed, bright light or temperature change, etc.
A type of reaction characterized by a release of energy to the surroundings.
What is exothermic?
Which of the following is not a compound: H2, H2O, or CO2?
What is H2, because it’s made of only one kind of atom, so it's an element and a molecule—not a compound.
This is a sign that a new substance has formed, and cannot be reversed easily.
What is a chemical change?
Valance electrons determine this property of an atom.
What is reactivity? (How easily it will form a bond with another atom)
C2H6O + 3O2 → 2CO2 + 3H2O
The number of atoms on the reactant side, and the number of atoms on the product side
What is 15 atoms of reactant and 15 atoms of product?
In a chemical equation, this is the number in front of a substance's chemical formula.
2H2 + O2 --> 2H2O
What is a coefficient?