Answer:
1.An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers ( 1 × 10−10 m, a ten-millionth of a millimeter, or 1/254,000,000 of an inch).
3.New elements aren't exactly discovered anymore. However, they can be made, using particle accelerators and nuclear reactions. A new element is made by adding a proton (or more than one) to a pre-existing element. This can be done by smashing protons into atoms or by colliding atoms with each other.
4.If an atom gains an electron, it becomes negatively charged.
If an atom loses an electron, it becomes positively charged.