🟢23.6: EXAM REVIEW: QUIZIZZ!

Which of the following is a definition of a molecule?

• A molecule is when elements separate into new types of elements.
• A molecule is comprised of at least two atoms joined together by a chemical bond.
• A molecule is a mixture of two elements.
• A molecule is a substance that will not bond with other elements.

Which of the following is the BEST definition of a compound?

• A compound is made up of a group of molecules
• A compound consists of only one atom.
• A compound is a type of chemical bond where elements are removed.
• A compound is an element that contains no electrons.

Which of the following is a TRUE statement?

• All elements prefer to hang out with other elements and form molecules
• Compounds always include the elements hydrogen and sodium
• Compounds include things we use in our everyday lives
• A molecule always has three types of elements present

Which of the following is a TRUE statement?

• Elements involved in a mixture cannot be separated and lose their chemical identities.
• Molecules are made up of compounds.
• Both hydrogen gas (H2) and water (H2O) are molecules.
• A mixture has chemical bonds between the substances.

What is a chemical reaction?

• A process where the arrangement of atoms the way they are connected together is changed.
• A process where the movement of atoms is changed.
• A process by which the shape of atoms is changed.
• A process where the arrangement of atoms but NOT the way they are connected together is changed.

Fill in the blank: The total number of atoms before a reaction happens is _____ the total number of atoms after a reaction happens.

• never equal to
• greater than
• unrelated to
• equal to
• less than

The materials present at the beginning of a chemical reaction are called the...

• reactants

• products

• yeild

• none of the above

The materials present at the end of a chemical reaction are called the...

• none of the above

• yeild

• reactants

• products

Which one is an example of physical change only?

• Frying an egg
• Melting Ice
• Fire
• none of the above

New compounds/products that are formed as a result of a chemical reaction have different properties as the reactants but...

• a different mass.
• the same mass.
• different atoms.
• the same compounds.