Answer:
Not positive but i think its when we burn fossil fuels.
Iron(II) oxide react with nitric acid to produce iron(III) nitrate, nitrogen dioxide and water. Chemical reaction<span>. Balancing </span>chemical<span> equations.</span>
Answer: The number 4 indicates 4 electrons.
Explanation: We are given an electronic configuration, which is:
Here,
- The letters denote the sub-shells of an element.
- The numbers written before the letters which are 1, 2 and 2 represents the Principle Quantum Number and these represents the energy level of the sub-shells.
- The number which are written in the superscripts which are 2, 2 and 4 denotes the electrons which are present in the sub-shell.
Hence, 4 indicates 4 electrons present in 2p sub-shell.