In a radio, pulse modulation refers to encoding a wave with information by:

a) adjusting the height of the waves
b) adjusting how many waves are produced per second
c) turning the wave on and off
d) changing the medium in which the waves travel

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Match each vocabulary term to its definition. 1. electrons neutral subatomic particles found in the nucleus of the atom 2. neutron lowest energy position of an electron in an atom 3. photon the path of an electron around the nucleus of an atom 4. ground state negatively charged, subatomic particles 5. protons packet of energy of specific size 6. element substance with only one type of atom 7. orbital positively charged, subatomic particles found in the nucleus of the atom

What accounts for an increase in the temperature of a gas that is kept at constant volume? a. energy has been removed as heat from the gas. b. energy has been added as heat to the gas. c. energy has been removed as work done by the gas. d. energy has been added as work done by the gas.