Answer:
selenium, fluorine and neon
Explanation:
the less valence electrons an element has, the more reactive.
selenium has 6 valence electrons
fluorine has 7 valence electrons
neon has 8 valence electrons
So, it is ordered from the least number of valence electrons to the most
They are the outer layer of the electron layers.
To calculate<span> the average </span>atomic mass<span>, multiply the fraction by the </span>mass<span> number for each isotope, then add them together.</span>
Answer:
<em>atomic number, the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus. Accordingly, the number of protons, which is always equal to the number of electrons in the neutral atom, is also the atomic number.</em>
Explanation:
<h3>brainlist please</h3>
Answer:
Got your back
Explanation:
If the ions derived from different atoms are isoelectronic species, then they all have same number of electrons in their electronic shells and will have got same electronic configuration but their nuclear charge will differ because of their difference in number of protons in the nucleus. With increase in number of protons in the nucleus the electrons are more attracted towards nucleus thereby causing the decrease in ionic radius. On this principle our problem will be solved
The given ions are
7N-3
→no. of proton
=7
and
no of electron
=10
8O-2
→
no. of proton
=8
and
no of electron
=10
9F-→
no. of proton=9
and no of electron=10
11Na→
no. of proton=11
and no of electron=10
12 Mg-3→
no. of proton=12 and
no of electron=10
Hence the increasing order of ionic radius is
12Mg-3<11Na+<9F-<8O-2<7N-3
To rmember ->For isoelectronic species lower the nuclear charge higher the radius
