1. Triassic
2. eon > era > period
3. The scientists study fossils and rock layers to find major changes.
They are very stable (not reactive).
This is because their outer shell has a total of 8 valence electrons. All elements strive to get towards a full outer shell, but since these elements already have a full outer shell, they are fairly unreactive.
The ions are as follows;
- As2O3 - As^3+, O^2-
- MnS - Mn^2+, S^2-
- VCl3 - V^3+, Cl^-
- NiF2 - Ni^2+, F^-
<h3>What is a cation and an anion?</h3>
A cation is a positive ion while an anion is a negative ion. Ionic compounds are composed o cations and anions.
The anions and cations in the ionic compounds in the table are shown below;
- As2O3 - As^3+, O^2-
- MnS - Mn^2+, S^2-
- VCl3 - V^3+, Cl^-
- NiF2 - Ni^2+, F^-
Learn more about cations and anions:brainly.com/question/4933048
#SPJ1
Chemical properties of elements are primarily determined by the electrons but not by neutrons. Therefore, the isotopes of the same element have similar chemical behavior. (a) The atomic number is 17, so there are 17 protons and 17 electrons. The mass number is 35, so there are 18 (=35-17) neutrons. Hope this helps. :)
Answer:
1) 1,... 2
2) 18
3) n= 3 and I=1
Explanation:
1) when l= 0, its an s-sub-level, and only 1 orbital is possible which can carry only 2-electrons
2) the maximum number of electron is given by 2n^2= 2×3^2= 18
3) in 3p, the coefficient of p is the value of n= 3 and l-value of P is 1
