The speed of a mechanical wave through a medium depends on the type of medium. It also depends on the type of mechanical wave. Which statement is true?

The statements are;

A) All waves travel at the same speed if no medium is present.

B) Electromagnetic waves require a medium, but mechanical waves do not.

C) All waves travel at the same speed through any medium.

D) Mechanical waves require a medium, but electromagnetic waves do not.

Statement D is true.

Mechanical waves require a medium, but electromagnetic waves do not.

Explanation:

The two types of waves are;

Mechanical waves and Electromagnetic waves.

Mechanical waves require a medium, such as an atmosphere or water, to enable it transport its energy. For example sound waves occur when you clap and thereby distort the air around.

Whereas, Electromagnetic waves do not require a medium to enable it transport its energy. A good example would be light. Normally, Electromagnetic waves are usually formed when the electric field and the magnetic field are perpendicular to each other.

So electromagnetic waves can transmit without a medium because electric and magnetic fields can exist independently without a medium.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

it should be all of them because it asks if you included all of those in your answer

explanation: