Answer:
.
Explanation:
Lithium is in the first column of the periodic table, so it will have 1 valence electron.
Bromine is in the seventh column of the periodic table, so it will have seven valence electrons.
They must combine in a way to reach 8.
When combining elements to form compounds, the "crisscross method" is used. Above Li would be a charge of +1, and above Br would be a charge of -1.
Cross the 1 from the top of Li to the bottom of Br, and so there is 1 Br.
Cross the 1 from the top of Br to the bottom of Li, and so there is 1 Li.
It is not written BrLi because chemists decided to order them the other way. Technically speaking, it isn't wrong, but the positive charge is normally put on the left and the negative charge is normally put on the right.
Answer:
b. lithium
Explanation:
Li the least likely, to lose an electron.
Answer:
3,4
Explanation:
Hydrogen has no other electron hence there is no screening of the valence electron by inner electrons. It is the lightest known element with a relative molecular mass of 2. Screening effect refers to the fact that inner or core electrons prevent the outermost electron from feeling the attractive force of the nucleus.
An atom that has 13 protons and 15 neutrons is isotope of Aluminium (answer C)
<u><em>Explanation</em></u>
- Isotope is a form of the same element with the equal number of protons but difference number of neutrons in their nuclei.
- In other words isotope has the same atomic number but different mass number.
- Atomic number of a element is determined by number of protons of an element.
- from the periodic table Aluminum in atomic number 13 therefore it has 13 protons <em>therefore an atom that has 13 protons and 15 neutrons is a isotope of Aluminium. </em>
