Unit 1 Vocab-Energy, Molecules, Chemical Rections

What is the term for the value you get when you add up all the numbers in a set and then divide by how many numbers there are?

• average

• sum

• median

• product

What is the smallest particle of an element that can exist, the basic building blocks for all matter?

• atom

• molecule

• cell

• proton

What is the term for the number of protons in the nucleus of an atom; determines what element the atom is?

• atomic number

• mass number

• isotope number

• atomic mass

What is the term for the change that happens when two or more substances act on each other to form a different substance?

• bond

• mixture

• solution

• reaction

What is a chain reaction of effects, where one change leads to others called?

• cascading consequences

• isolated event

• static outcome

• random occurrence

• single effect

What is a chemical that makes a chemical reaction happen faster called?

• catalyst

• solvent

• reactant

• inhibitor

What is a change in how the atoms of one or more substances are arranged; it leads to the formation of a new substance and is usually not reversible called?

• chemical change

• physical change

• mixture

• solution

What are symbols and numbers to show the types and amounts of atoms in a molecule or compound called? Example: H2O for water.

• chemical formula

• atomic number

• isotope notation

• molecular weight

What is the process called when chemicals combine to cause new substances to be formed?

• chemical reaction

• evaporation

• filtration

• condensation

What is it called when two or more objects or particles hit each other?

• collision

• reflection

• diffusion

• fusion