Answer:
Valence
Explanation:
In an atom, the electrons at the outermost energy level is called as valence electrons. It is the valence electrons which participates and interacts with the other atoms and form bonds. The valence electrons of an atoms are important as they depict the chemical properties of an element.
Thus the valence electrons resides the outermost shell and surrounds the atomic nucleus.
Answer:
A
Explanation:
There are different mechanisms for transport of molecules across the cell membrane. One kind of this transport is facilitated diffusion, this is a form of passive transport, not requiring any ATP (the opposite would be active transport, where it does require ATP.
Simple diffusion does require special transport proteins, and neither does osmosis. Filtration is a technique used for sterilisation of water, where any impurities can be drawn out of the liquid
Answer:
One
Explanation:
The only star in our solar system is the Sun.