The right answer is 2.
The number of protons contained in a nucleus (called an atomic number) is characteristic of a chemical element. For a given atomic number, the number of neutrons defines different "types" of this element: isotopes. The variation of the number of protons of the nucleus of an atom, during a nuclear reaction for example, causes a change of the element studied.
For a single atom, the charge is the number of protons minus the number of electrons
Answer:
Tendons connect the skeletal system to the muscular system by attaching muscle to bone. When muscle contracts, the tendon acts on the bone, causing movement. Joints, the point at which two or more bones connect, can be fixed, slightly movable, or freely movable.
As the air molecules move through the valve they have friction as they hit the walls, and its this friction that causes it to heat up.
The Kj of heat that are needed to completely vaporize 1.30 moles of H2O if the heat of vaporization for water is 40.6 Kj/mole is calculated as below
Q(heat) = moles x heat of vaporization)
=1.30 mol x40.6 kj/mol= 52.78 Kj is needed
