Physical Science Final Review

How many electrons are needed in the outer energy levels of most atoms for the atom to be chemically stable?

• 8

• 6

• 2

• 4

Matter with no definite volume and no definite shape is a ____.

• liquid

• solid

• gas

• plasma

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A truck with a mass of 1500 kg is accelerating at a rate of 5 m/s². How much force does this require?

• 7500 N

• 300 N

• 2800 N

• 500 N

Answer explanation

To calculate the force, use the formula F = m * a, where m = 1500 kg and a = 5 m/s^2. Therefore, F = 1500 kg * 5 m/s^2 = 7500 N.

Tags

NGSS.MS-PS2-2

Determine whether the following equation is balanced or unbalanced. H₄ + O₂ ---> 2H₂O

• Balanced

• Unbalanced

Answer explanation

The given equation is balanced because the number of atoms of each element is the same on both sides of the equation.

Tags

NGSS.MS-PS1-5

Which coefficients would balance this chemical equation? _Fe₂O₃ ---> _Fe + _O₂

• 2,1,2

• 2,4,3

• 1,1,1

• 1,3,2

Answer explanation

To balance the equation, we need 2 Fe2O3, 4 Fe, and 3 O2. Therefore, the correct coefficients are 2, 4, 3 respectively, making the balanced equation: 2Fe2O3 ---> 4Fe + 3O2.

Tags

NGSS.MS-PS1-5

Which coefficients would balance this chemical equation? _K + _Cl₂ ---> _KCl

• 1,1,1

• 1,2,2

• 1,1,2

• 2,1,2

Answer explanation

To balance the equation, we need 2 atoms of K on the left side and 2 atoms of Cl on the right side, resulting in coefficients 2,1,2 for K, Cl2, and KCl respectively.

Tags

NGSS.MS-PS1-5

What is this?

This airplane is traveling at 500 mph, West

• Speed

• Velocity

• Acceleration

Answer explanation

Velocity is the correct choice because velocity includes both speed and direction, which in this case is 500 mph, West.

Tags

NGSS.MS-PS3-1

Billy was driving his car and when he reached the tollbooth, he slowed from 190m/s to 12m/s in 20 seconds. What is the acceleration?

• -8.9m/s²

• 8.9m/s²

• 9.8m/s²

• -9.8m/s²

Answer explanation

The acceleration can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. Substituting the values, we get acceleration = (12 - 190) / 20 = -8.9m/s². Therefore, the correct answer is -8.9m/s².

Tags

NGSS.MS-PS2-2

The speed boat's speed increased from 0 m/s to 24 m/s in a time span of 12 seconds. What is the acceleration?

• 4 m/s²

• 2 m/s²

• 8 m/s²

• 6 m/s²

Answer explanation

The acceleration can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. Substituting the values, we get acceleration = (24 m/s - 0 m/s) / 12 s = 2 m/s². Therefore, the correct answer is 2 m/s².

What does this graph represent?

• Constant Speed

• Acceleration

• Not moving

Answer explanation

The graph represents constant speed because there is no change in the slope, indicating a consistent velocity over time.

Tags

NGSS.MS-PS3-1