1) The trails left by an electron as it moves around the nucleus
The electron model dictates that the electrons have no fixed position so it traces their path.
2) 8
Atomic number is equivalent to proton number
3) Its mass is lowered, but it is still the same element.
The element's identity is due to the number of protons; however, neutrons play a large role in an atom's mass. Thus, the mass will decrease but the element will be the same. Such variants are called isotopes.
Temperature. Water is an example. When water is at room temp. its liquid. When water is at boiling temp. It is a gas. And when water is at freezing temp. Its a solid.
MgCl2(aq) is an ionic compound which will have the releasing of 2 Cl⁻ ions ions in water for every molecule of MgCl2 that dissolves.
MgCl2(s) --> Mg+(aq) + 2 Cl⁻(aq)
[Cl⁻] = 0.098 mol MgCl2/1L × 2 mol Cl⁻ / 1 mol MgCl2 = 0.20 M
The answer to this question is [Cl⁻] = 0.20 M