Which statement is true for both electromagnetic waves and mechanical waves?
A. They must use matter to transmit the energy of a disturbance.
B. They vibrate in the direction that is parallel to their direction of
travel.
C. They carry energy over a distance.
D. They transfer matter through empty space.

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

c. electrical charges of ionic bonds.