25-26 Unit 1 Vocabulary-Energy, Energy Transfer, Molecules

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

• average

• sum

• product

• median

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 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 change that happens when two or more substances act on each other to form a different substance called?

• bond

• mixture

• solution

• dissolving

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

• cascading consequences

• isolated incident

• random occurrence

• static event

• single outcome

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 formation

• dissolving

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

• chemical formula

• atomic number

• isotope notation

• molecular weight

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

• chemical reaction

• evaporation

• condensation

• filtration

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

• collision

• reflection

• diffusion

• expansion