<span>because it is a pattern; airgo cycle</span>
Answer:
element
Explanation:
elements consist of pure substances
Answer:
Explanation:
The oxidation number is an integer that represents the number of electrons that an atom receives or makes available to others when it forms a given compound.
The oxidation number is positive if the atom loses electrons, or shares them with an atom that has a tendency to accept them. And it will be negative when the atom gains electrons, or shares them with an atom that has a tendency to give them up.
Chemical compounds are electrically neutral. That is, the charge that all the atoms of a compound contribute must be globally null. That is, when having positive or negative charges in a compound, their sum must be zero.
There are some rules for determining oxidation numbers in compounds. Among them it is possible to mention:
- Hydrogen (H) has an oxidation number +1 with nonmetals and - 1 with metals.
- Oxygen (O) presents the oxidation number -2
- Fluorine F has a unique oxidation state -1
Then:
- NOF: N+(-2)+(-1)=0 → N=3 → oxidation number of nitrogen (N) is +3, oxidation number of oxygen (O) is -2 and oxidation number of fluorine (F) is -1.
- ClF₅: Cl + 5*(-1)=0 → Cl= 5 → oxidation number of chlorine (Cl) is +5 and oxidation number of fluorine (F) is -1.
- H₂SO₃: 2*(+1)+S+3*(-2)=0 → S=4 → oxidation number of hydrogen (H) is +1, oxidation number of oxygen (O) is -2 and oxidation number of sulfur (S) is +4.
The study of plants, plant life cycles, photosynthesis, plant parts, etc. is under botany (study of plants).
Answer:
The electron from the ground state to occupy a next energy level. In this case,we say that the electron is excited
