Answer:
(a) I⁻ (charge 1-)
(b) Sr²⁺ (charge 2+)
(c) K⁺ (charge 1+)
(d) N³⁻ (charge 3-)
(e) S²⁻ (charge 2-)
(f) In³⁺ (charge 3+)
Explanation:
To predict the charge on a monoatomic ion we need to consider the octet rule: atoms will gain, lose or share electrons to complete their valence shell with 8 electrons.
(a) |
I has 7 valence electrons so it gains 1 electron to form I⁻ (charge 1-).
(b) Sr
Sr has 2 valence electrons so it loses 2 electrons to form Sr²⁺ (charge 2+).
(c) K
K has 1 valence electron so it loses 1 electron to form K⁺ (charge 1+).
(d) N
N has 5 valence electrons so it gains 3 electrons to form N³⁻ (charge 3-).
(e) S
S has 6 valence electrons so it gains 2 electrons to form S²⁻ (charge 2-).
(f) In
In has 3 valence electrons so it loses 3 electrons to form In³⁺ (charge 3+).
It changes to chemical energy
1) The answer is: 2 moles of oxygen molecules.
Balanced chemical reaction of methane combustion:
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g).
Coefficients with the lowest ratio indicate the relative amounts of substances in a reaction.
In fronf of oxygen molecule is coefficient 2.
2) The answer is: 4 moles of oxygen atoms.
In one molecule of oxygen there are two oxygen atoms, so in two molecules there are four oxygen atoms.
Answer:
Two electrons.
Explanation:
Calcium is the element of second group and forth period. The electronic configuration of Calcium is - 2, 8, 8, 2 or 
There are 2 valence electrons of Calcium.
Iodine is the element of seventeenth group and fifth period. The electronic configuration of Iodine is - 2, 8, 18, 18, 7 or ![[Kr]4d^{10}5s^25p^5](https://tex.z-dn.net/?f=%5BKr%5D4d%5E%7B10%7D5s%5E25p%5E5)
There are 7 valence electrons of iodine.
Calcium iodide, 
is formed when 2 valence electrons of calcium are loosed and they are gained by 2 atoms of iodine.
