Unit 7 Science Test

• Neutrons
• Protons
• Atomic Mass
• Electrons

Most of the volume of an atom is occupied by —

• protons
• empty space
• a gas
• the nucleus

The quantity of which subatomic particle determines the element’s identity?

• Neutrons
• Protons
• Valence Electrons
• Total Electrons

Which of these groups in the Periodic Table is made up primarily of elements that are gases at room temperature?

• Group 1
• Group 2
• Group 12
• Group 18

Which of the following groups in the Periodic Table is made from reactive metals?

• Group 1
• Group  6
• Group  17
• Group  18

The most reactive metal is one with -

• 4 valence electrons
• 1 valence electrons
• 2 valence electrons
• 3 valence electrons

When an object is acted on by unbalanced forces, the object will always —

• accelerate
• continue in the same direction
• continue at the same speed
• come to a stop

One of the laws of motion states, "An object in motion stays in motion unless an unbalanced force acts upon it." On Earth, objects always seem to eventually come to a stop when more force is not being applied.

What force is causing the objects to eventually stop moving?

• Mass
• Friction
• Weight
• Gravity

Which of the following statements best describes how the speed and velocity of an object differ?

• Velocity specifies speed and direction, while speed has no specific direction.
• Velocity specifies speed, while speed includes a specific direction.
• Velocity specifies a change in speed over time, while speed specifies a change in distance over time.
• Velocity specifies a change in distance over time, while speed specifies a change in velocity over time.

Which two continents did Alfred Wegener think looked like they fit together like puzzle pieces?

• North America and South America
• Europe and Africa
• North America and Europe
• South America and Africa