Answer:
photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.
It called cation, Well, When an atom gains or loses an electron, it
attains a net charge and becomes an ion. When electrons are lost, the
resulting ion is called cation and when electrons are gained, the
resulting ion is called an anion. So, Cations have a net positive
charge, while anions have a net negative charge. it is true.
Three that is the answer to your question