Reactivity is a chemical
property of a substance. According to EPA regulations, it is normally unstable
and readily
undergoes violent change without
detonating. it can explode or violently react when exposed to water, when
heated, or under STP.
C would be the right answer
Formula for density is mass / volume.
100 ml is volume. 76.5g of cooking oil is
the mass.
Therefore
76.5/100 = .765g/ml
The question is incomplete, the complete question is;
Which statement describes a difference between electromagnetic and mechanical waves?
A. Mechanical waves cannot be longitudinal, but electromagnetic waves can.
B. Electromagnetic waves cannot move particles, but mechanical waves can.
C. Electromagnetic waves do not require a medium, but mechanical waves do.
D. Mechanical waves do not transfer energy, but electromagnetic waves do.
Answer:
Electromagnetic waves do not require a medium, but mechanical waves do.
Explanation:
A wave is defined as a disturbance along a medium which transfers energy. Waves may be classified as mechanical waves or electromagnetic waves based on their medium of propagation.
A mechanical wave requires a material medium for propagation. An example of a mechanical wave is sound waves. Sound waves are propagated in air.
Electromagnetic waves do not require a material medium for propagation. They can travel through space. An example of electromagnetic waves is light waves.
