Chemisty A - Energy Pre-Test 100%

A welding torch produces a flame by burning acetylene fuel in the presence of oxygen. The energy released from the acetylene fuel is then used to melt a metal.Which energy transformation happens during this process? Chemical energy turns into thermal energy. Kinetic energy turns into potential energy. Thermal energy turns into electromagnetic energy. Potential energy turns into chemical energy.

(A) Chemical energy turns into thermal energy.

Which form of energy is directly related to the measure of the average kinetic energy of the particles in a substance? thermal energy potential energy mechanical energy electromagnetic energy

(A) thermal energy

According to the law of conservation of energy, what will most likely happen in a closed system? Energy will be exchanged along with matter. Energy will be exchanged, but matter will not be exchanged. Energy will be created along with matter. Energy will be destroyed, but matter will not be destroyed.

(B) Energy will be exchanged, but matter will not be exchanged.

When an object falls toward the ground due to gravity, what type of energy becomes kinetic energy? chemical electromagnetic potential thermal

(C) potential

Which energy change best relates to a boulder that is rolling down the side of a hill? potential energy transforming into kinetic energy mechanical energy transforming into thermal energy potential energy transforming into electromagnetic energy mechanical energy transforming into electromagnetic energy

(A) potential energy transforming into kinetic energy

Which is the best term to use when describing the energy of motion? chemical kinetic potential thermal

(B) Kinetic

Which scenario would adhere to the law of conservation of energy? Energy is created when water freezes. Energy is destroyed when sugar is burned. Energy stays inside molecules permanently. Energy is transferred when atoms are rearranged.

(D) Energy is transferred when atoms are rearranged.

A generator contains a coil that spins to produce an electric current. How is energy transformed by using a generator? Thermal energy is transformed to potential energy. Thermal energy is transformed to mechanical energy. Chemical energy is transformed to electromagnetic energy. Mechanical energy is transformed to electromagnetic energy.

(D) Mechanical energy is transformed to electromagnetic energy.

Chemical energy in burning wood is changed into thermal energy. The thermal energy is absorbed by water, which boils to produce steam. The thermal energy is changed into kinetic energy in the moving steam. The kinetic energy is used to turn a turbine, which converts the kinetic energy into electricity. Which sentence best describes this system? It involves only energy transfer. It involves only energy transformation. It involves both energy transformation and energy transfer. It does not involve either energy transformation or energy transfer.

(C) It involves both energy transformation and energy transfer.

In a chemical reaction occurring in an open beaker, the reactants have a mass of 10.0 g and contain 1000 J of energy. The products in the beaker contain a mass of 5.0 g and 500 J of energy. Which best explains the difference in energy and mass as reactants are converted to products? kinetic energy closed systems law of conservation of energy electromagnetic energy

(C) law of conservation of energy