Which of the following statements is true with regard to transverse and longitudinal waves?
group of answer choices

both transverse waves and longitudinal waves have motion parallel to velocity.

both transverse waves and longitudinal waves have motion perpendicular to velocity.

transverse waves have motion parallel to velocity, while longitudinal waves have motion perpendicular to velocity.

transverse waves have motion perpendicular to velocity, while longitudinal waves have motion parallel to velocity.

D (The last answer)

Explanation:

In a transverse wave, particles oscillate perpendicular to the direction of wave motion.

In a longitudinal wave, the oscillations of particles are parallel to the direction of propagation.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.