Matter is the basis for everything. Anything that exists has matter. Dark matter are anomalies that cannot account for "missing matter".

Matter does not contain the solar energy and radio signals that travel through "empty space".

mass is defined as the amount of matter in an object

Matter does.

First the human body is wholly composed of matter. The body takes in matter to be broken down through digestion, to replenish and fuel the body. This matter is converted into new molecules constantly. The body also excretes gaseous, liquid and solid matter through respiration, metabolism, and excretion of waste.

Matter can be dead or alive.