The moon's gravitational force
Answer:
Electrons
Explanation:
According to the modern atomic theory, atoms are made-up of smaller subatomic particles in the nucleus. The nucleus contains two types of subatomic particles, protons and neutrons. The protons have a positively electrical charge and the neutrons have no charge. The electrons have a negative electrical charge and are able to move around the nucleus. An atom usually contains an equal number of positively charged protons and negatively charged electrons. This makes the atom itself electrically neutral. The electrons exist at different energy levels, called shells, around the nucleus where they revolve freely in a constant motion.
Answer:
Birds and bats have homologous limbs because they are both ultimately derived from terrestrial tetrapods, but their flight mechanisms are only analogous, so their wings are examples of functional convergence.
