Protons have a positive charge. The number of protons in a nucleus determines the identity of the atom (element) and this number is called the atomic number.
D. Proton
Energy and matter characterize both physical and biological systems. These systems are defined both by the types of energy and matter they contain and by how that matter and energy move through and between systems. ... This means that energy and matter can change forms but cannot be created or destroyed.
The sun is a source of energy for all living things.
