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A hockey puck slides on ice.

a
Newton's First Law of Motion
b
Newton's Second Law of Motion
c
Newton's Third Law of Motion

My car hits a mosquito, and the mosquito hits back, equally.

a
Newton's First Law of Motion
b
Newton's Second Law of Motion
c
Newton's Third Law of Motion

Mrs. Hankinson has a zero total external forces acting on her - she keeps moving at a constant velocity, if she is already moving.



a
Newton's First Law of Motion
b
Newton's Second Law of Motion
c
Newton's Third Law of Motion

A student looks up an element on the periodic table. The table says that the atomic number of the element is 12 and the mass number of the element is 40. What information do these two numbers convey about the element?

a
The element has 40 protons and 12 neutrons
b
The element has 12 protons and 12 neutrons
c
The element has 12 protons and has 28 neutrons
d
The element has 28 protons and 40 neutrons

In all elements in a group, the thing that is the same is the:

a
Number of electrons in the valence shell
b
Number of electrons
c
Number of protons
d
Number of neutrons
How many oxygen atoms are in the compound below:

Cu3(PO4)2

a
4
b
2
c
8
d
6

1 answer

Here are the answers to your questions:

1. A hockey puck slides on ice.

  • Answer: a) Newton's First Law of Motion
    Reason: An object in motion stays in motion unless acted upon by a net external force.

2. My car hits a mosquito, and the mosquito hits back, equally.

  • Answer: c) Newton's Third Law of Motion
    Reason: For every action, there is an equal and opposite reaction.

3. Mrs. Hankinson has a zero total external forces acting on her - she keeps moving at a constant velocity, if she is already moving.

  • Answer: a) Newton's First Law of Motion
    Reason: An object at rest or in uniform motion will stay in that state unless acted upon by an external force.

4. A student looks up an element on the periodic table. The table says that the atomic number of the element is 12 and the mass number of the element is 40. What information do these two numbers convey about the element?

  • Answer: c) The element has 12 protons and has 28 neutrons
    Reason: The atomic number (12) indicates the number of protons. The mass number (40) is the sum of protons and neutrons, so to find neutrons, we subtract protons from the mass number: 40 - 12 = 28 neutrons.

5. In all elements in a group, the thing that is the same is the:

  • Answer: a) Number of electrons in the valence shell
    Reason: Elements in the same group have the same number of electrons in their outermost valence shell, which determines their chemical properties.

6. How many oxygen atoms are in the compound below: Cu3(PO4)2?

  • Answer: b) 8
    Reason: There are 2 phosphate ions (PO₄) in the formula, and each phosphate contains 4 oxygen atoms, so 2 × 4 = 8 oxygen atoms total.