<h2>
Answer:</h2>
Valance electrons can be determined by <u>Group</u> on the periodic table
<h2>
Explanation:</h2>
- Valence electrons are the electrons present in the outermost shell of an atom. We can determine the total number of valence electrons present in an atom by checking at its Group in which it is placed in the periodic table. For example, atoms in Groups 1 the number of valence electron is one and for group 2 the number of valence electrons is 2.
- The groups have number of valance electrons as follow:
Group 1 - 1 valence electron.
Group 2 - 2 valance electrons.
Group 13 - 3 valence electrons.
Group 14 - 4 valance electrons.
Group 15 - 5 valence electrons.
Group 16 - 6 valence electrons.
Group 17 - 7 valence electrons.
Group 18 - 8 valence electrons.
Result: No of valence electron can be determined by the group no. of the element.
Answer:
MgO- magnesium oxide
Cu(NO3)2- copper(11)nitrate
Li2CO3- lithium carbonate
Explanation:
a positively charged nucleus is surrounded by mostly empty space.
Explanation:
a) Using Beer-Lambert's law :
Formula used :
where,
A = absorbance of solution = 0.945
c = concentration of solution = ?
l = length of the cell = 1.20 cm
= molar absorptivity of this solution =
(
)
14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.
b) 
1 L of solution contains 
moles of red dye.
Mass of moles of red dye:
c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.
Concentration of red dye solution = 
Concentration of red solution after dilution = c'
The final concentration of the diluted solution is 
Answer:
pH= 8.45
Explanation:
when working with strong accids pH = -log(Concentration)
so -log(3.58e-9) = 8.446
