1)
Compounds may be represented by chemical formulas. In the chemical formula for water which is H20, the 2 which represents the number of hydrogen atoms is called
A) the reactant.
B) the subscript.
C) the coefficient.
D) the atom factor.
2)
Carbon dioxide can be represented by the chemical formula
A) C2O
B) CO2
C) Ca2O
D) CaO2
3)
As a roller coaster goes downhill
A) kinetic energy is converted into potential energy.
B) potential energy is converted into kinetic energy.
C) electrical energy is converted into potential energy.
D) potential energy is converted into electrical energy.
4)
Which of these would have the greatest potential energy?
A) A roller coaster at the top of a hill.
B) A roller coaster half-way up the hill.
C) A roller coaster half-way down the hill.
D) A roller coaster at the bottom of the hill.
An object that has kinetic energy must be
A) at rest.
B) stopped.
C) in motion.
D) at an elevated position.
7)
Which represents potential energy?
A) bread baking
B) lawnmower cutting grass
C) car racing downhill
D) weed whacker full of gas
8)
A skateboarder is standing at the top of a tall ramp waiting to begin a trip. The skateboarder has
A) kinetic energy only.
B) potential energy only.
C) both kinetic and potential energy.
D) neither kinetic or potential energy.
9)
Which of these is NOT a mixture?
A) baking soda
B) salt and water
C) iron filings and sand
D) metal paper clips and plastic paper clips
Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2O. The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule.
In the chemical formula for water which is H20, the 2 which represents the number of hydrogen atoms is called subscript.
Carbon dioxide can be represented by the chemical formula: CO2.
As a roller coaster goes downhill, the potential energy is converted into kinetic energy.
A roller coaster at the bottom of the hill would have the highest potentialenergy.
An object that has kinetic energy must be in motion
Weed whacker full of gas represents potential energy
A skateboarder standing at the top of a tall ramp waiting to begin a trip has potential energy only.
Baking soda is not a mixture
QUESTION 1:
Water is a chemical compound containing hydrogen and oxygen in the ratio 2:1. Hence, water has a chemical formula of H2O.
QUESTION 2:
Carbon dioxide is a chemical compound containing carbon and oxygen in the ratio 1:2. Hence, carbon dioxide has a chemical formula of CO2.
QUESTION 3:
Potential energy is the energy due to the position of an object while kinetic energy is the energy due to motion. Hence, as a roller coaster goes downhill, potential energy is converted into kinetic energy.
QUESTION 4:
A roller coaster at the bottom of the hill is at the most stationary position, hence, will possess the highest potential energy.
QUESTION 5:
As described in question 3, an object that possess kinetic energy must be in motion.
QUESTION 6:
A weed whacker full of gas is the only stationary object among the options, hence, it is an example that represents potential energy.
QUESTION 7:
A skateboarder standing at the top of a tall ramp waiting to begin a trip has potential energy only because it is still in a stationary state.
QUESTION 8:
A mixture is a substance containing more than one different substances that are not chemically combined together. In the options provided, baking soda is a compound because the elements that make it up are chemically bonded.
