End of Year Science Review

Elements with seven valence electrons —

• are highly reactive

• are highly stable

• have a high mass

• have a low mass

The atoms of a certain element each contain 11 protons and 1 valence electron. Which statement correctly identifies this element and describes its chemical reactivity?

• The element is sodium, and it is highly reactive

• The element is fluorine, and it is highly reactive

• The element is sodium, and it is not very reactive

• The element is fluorine, and it is not very reactive

Tags

NGSS.MS-PS1-1

Sulfur is a nonmetal. Of the following, the physical characteristic that is most

likely to describe a sample of sulfur is —

• a shiny appearance

• brittleness

• malleability

• ductility

Potassium nitrate is a compound used in some fertilizers. Its chemical formula is KNO3. How many TOTAL atoms are in each unit of potassium nitrate?

• 2

• 5

• 3

• 9

Tags

NGSS.MS-PS1-1

Look at the pictures above. A shows the bag before the vinegar and baking soda are mixed together, and B shows it after they are mixed together. In which picture do the contents of the bag have the greater mass?

• The mass is greater in A—before they are mixed.

• The mass is greater in B—after they are mixed.

• The mass is the same in both.

• The mass depends on the temperature.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is the best clue that a chemical reaction has taken place?

• Change in color

• Change in state

• Change in particle size

• Change in volume

Tags

NGSS.MS-PS1-2

A student uses a magnet to move a .04 kg ball bearing. The magnet exerts a force of 4N, which causes the ball bearing to begin moving. What is the acceleration of the ball bearing when it begins to move?

• .01 m/s2

• .16 m/s2

• 3.96 m/s2

• 100 m/s2

Tags

NGSS.MS-PS2-2

While practicing in a simulator, an astronaut experienced an acceleration of 26 m/s2. The astronaut's mass was 63.0 kg. In Newtons, what force did the astronaut experience?

• 2.42 N

• 37 N

• 1638 N

• 42,588 N

Tags

NGSS.MS-PS2-2

In this model, which particle determines the reactivity of this atom?

• Particle W

• Particle X

• Particle Y

• Particle Z

Tags

NGSS.MS-PS1-1

Observing means

• using one or more of your senses to gather information

• making a model of something you can't see with your own eyes

• making a forecast of something that will happen

• making a guess as to what is happening

Tags

NGSS.1-ESS1-1

NGSS.2-PS1-1

NGSS.K-2-ETS1-1

NGSS.K-ESS2-1

NGSS.K-LS1-1