Unit 1 - 1.1 Nature of Substances

What is an element?

• A substance made up of a single type of atom

• A substance made from two or more elements

• A mixture of compounds

• A chemical reaction product

What is an ion?

• An atom that has lost or gained at least one electron

• A molecule with a neutral charge

• A compound with a positive charge

• A mixture of atoms

What is the charge of Group 1 metal ions?

• 0

• 1+

• 2+

• 1-

How is the overall charge of a compound determined?

• By adding the charges of all atoms

• By balancing the number of positively and negatively charged ions

• By counting the number of electrons

• By measuring the mass of the compound

What is a mixture?

• A chemical reaction product

• A combination of elements or compounds not chemically combined

• A single type of atom

• A compound with a fixed ratio

What do chemical equations show in a reaction?

• The color change of substances

• The ratio of molecules reacting

• The temperature change of substances

• The speed of the reaction

What is effervescence in a chemical reaction?

• Release of a gas

• Change in color

• Increase in temperature

• Formation of a solid

What is the mass number of an atom?

• Number of protons

• Number of electrons

• Sum of protons and neutrons

• Number of neutrons

How is the percentage mass of an element 'X' in a compound calculated?

• Mass of element X in formula / Total mass of all atoms in formula

• Total mass of all atoms in formula / Mass of element X in formula

• Mass of element X in formula / Total mass of all atoms in formula x 100

• Total mass of all atoms in formula / Mass of element X in formula x 100

What is the mass of 1 mole of carbon?

• 12g

• 53g

• 106g

• 24g