Grade 7 Unit 1 Common Assessment

What happens to water molecules when a large quantity of thermal energy is added to water in a liquid state?

• The more energy added, the greater the attraction between the molecules.
• The molecules gain energy, move farther apart, and become a gas.
• The water molecules become packed closer together, and their temperature increases.
• Each water molecule gives up energy and eventually stop moving.

Students were asked to draw a concept map of changes in matter at the molecular level. Based on the diagram, which of the following statements is true?

• Arrow A= particles become more tightly packed.
• Arrow B= the pressure of the substance decreases.
• Arrow C= energy of particles increases.
• Arrow D= particles become more widely spaced.

Which of the following is true about how hydrogen and oxygen can combine to form molecules.

• Hydrogen and oxygen can combine in many ways to form different molecules.
• Two atoms of hydrogen are always required to bond with two atoms of oxygen.
• When oxygen combines with hydrogen to make a molecule, water will always be produced.
• Molecules composed of hydrogen and oxygen must have at least four atoms.

Which of the following best explains the relationship between molecules and atoms?

• Atoms are molecules that have a charge.
• Atoms have smaller parts, called molecules.
• Molecules are made up of two or more atoms.
• Molecules are atoms that have no mass.

Organisms are mostly made up of all of the following elements except

• carbon
• aluminum
• oxygen
• nitrogen

Elements that are normally in a gas form, that are dull, brittle, and poor conductors

• Metals
• Nonmetals
• Metalloids
• Solids

Usually solid elements that are good conductors, malleable, ductile, and shiny

• Metals
• Nonmetals
• Metalloids
• Semiconductors

Semi-conductors have properties of both metals and nonmetals. An example of a semi-conductor is

• Carbon
• Oxygen
• Magnesium
• Silicon

What is true of the particles of a substance that is heated or cooled?

• The particles size changes
• The particles motion changes
• The particles size and motion changes
• Neither the size nor the motion of the particles change

What are the nonliving parts of an environment called?

• Biotic
• Organism
• Abiotic
• Population