A. 1
B. 4
C. 5
D. 3
E. 2
The correct answer is E. 2
Answer:
ichedgepeth
Explanation:
beginner because it's tough than other things
Answer:
1.5 x 10²²atoms
Explanation:
Given parameters:
Mass of Br = 1.98g
Unknown:
Number of atoms
Solution:
A mole of a substance is the amount of substance contained in the avogadro's number of particles.
To solve this problem, we must first find the number of moles present in the given mass of the Br atom:
Number of moles =
=
= 0.025mole.
Now we know that:
1 mole = 6.02 x 10²³
0.025 mole = 0.025 x 6.02 x 10²³ = 1.5 x 10²²atoms
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.