Atoms and Molecules

What is a chemical reaction?

• A process that involves the rearrangement of the molecular or ionic structure of a substance.

• A method of separating mixtures into their individual components.

• A technique used to measure the temperature of a substance.

• A way to combine different elements without changing their properties.

What is a substance made up of one or more molecules?

• Salt

• Water

• Oxygen

• Carbon Dioxide

What is a chemical bond?

• A temporary attraction between atoms that does not lead to compound formation.

• A lasting attraction between atoms that enables the formation of chemical compounds.

• A type of bond that only occurs in metals.

• A weak interaction that can be easily broken.

What is the mass number of an atom?

• The total number of protons and neutrons in the nucleus.

• The total number of electrons in the atom.

• The number of protons only in the nucleus.

• The average mass of all isotopes of an element.

What are the particles found in the nucleus of an atom?

• Electrons and protons

• Protons and neutrons

• Neutrons and positrons

• Photons and electrons

What is the difference between an element and a compound?

• An element is a pure substance made of one type of atom, while a compound is made of two or more different types of atoms chemically bonded.

• An element can be broken down into simpler substances, while a compound cannot.

• An element is a mixture of different atoms, while a compound is a single type of atom.

• An element is always a solid, while a compound can be a gas or liquid.

What term defines a substance formed by the combination of elements in fixed amounts?

• Element

• Compound

• Mixture

• Solution

What is all matter made of?

• Molecules

• Atoms

• Cells

• Particles

What is the charge of an electron?

• Positive

• Neutral

• Negative

• Variable

What is the atomic number of an element?

• The number of protons in the nucleus of an atom.

• The total number of electrons in an atom.

• The number of neutrons in the nucleus of an atom.

• The mass of an atom measured in atomic mass units.