Answer is: 2. atomic number.
Atomic number is unique and defines an element. Atomic number (Z) is total number of protons in an atom.
For example, nitrogen atom (N-14) has 7 protons (p⁺), 7 electrons (e⁻) and 7 neutrons (n°). Protons (positive charge) and neutrons are in the nucleus of atom, electrons (negative charge) are bound to the nucleus in spherical shells. Nitrogen is an element with atomic number 7. Mass number (A) is the total number of protons and neutrons in a nucleus. Nitrogen mass number is 14 (A = p⁺ + n°; A = 14).
Student B because it requires a hypothesis
Answer:
It causes light to slow down significantly
Explanation:
The index of refraction of a substance describes the speed of light in that substance, as a ratio of the speed of light in vacuum to its speed in that substance.
just search it up and there is your answer
They may break bonds,form new compounds, new ions etc...
Answer:
Where are the question's???
Explanation: