Explanation:
The total number of electrons in the outermost shell orbitals gives the valency or the combining power of the element concerned.
The number is the same as the number of electrons gained or lost or shared in interatomic bonding.
The number of electrons lost denotes the charges on ions that they form.
On the periodic table, a group or family have the same number of electrons in their outermost shell. The group number denotes the amounts of electrons in their outer shell.
Here is a possible list of valencies of elements from valence electrons;
Number of valence electrons Possible valencies
1 1
2 2
3 3, 1
4 4, 2
5 5, 3
6 6, 2
7 7 , 1
8 8,0
These valencies are the charges on the ions. The bold ones are the preferred ones.
Group 8 elements do not carry any charges .
learn more:
Valence shell of carbon brainly.com/question/5274289
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<span>The value of enthalpy of a reaction can be a useful tool in determining the type of reaction it is. If the enthalpy is negative the reaction is exothermic and if the enthalpy is positive the reaction is endothermic. Hope this answers the question. Have a nice day.</span>
Step 1) identify the solvent and solute
solvent= H2O
solute= NaOH
Step 2) Assume that there are 100 grams total. Assume that the percent of the compound present is the number of grams present as well
100 g total
16g NaOH
84g H20
Step 3) convert grams to moles
84g H2O =4.64 mol H2O
19 g NaOH = 0.400 mol NaOH
Step 4) mole fraction = moles A/(mol A + mol B +....)
X= 0.400/(0.400 + 4.64) = 0.079 (no units)
Step 5) convert g of solvent to kg
84 g H2O = 0.084 kg
Step 6) molality = moles of solute/ kg of solvent
molality = 0.400 mol NaOH/ 0.084 kg H2O
molality= 4.76 m
Answer: Catalyst B
Explanation:
Allows reactions to proceed at much lower energy levels than without.
