Answer:
Explanation:
The formation of a gas is a clue to chemical changes. The bubbles of gas that you observed form when an antacid is dropped into water is an example of change. ... After ice melts into liquid water, you can refreeze it into solid ice if the temperature drops. Freezing and melting are physical changes.
Glucose. <span>C6H12O6. Photosynthesis produces it and it is a reactant for cellular respiration. </span>
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.