The valence electrons are determined by the column that the element falls in.
Column 1 has 1 valence electron
Column 2 has 2 valence electrons
Column 13 has 3 valence electrons
Column 15 has 5 valence electrons
column 16 has 6 valence electrons
column 17 has 7 valence electrons
Elements are trying to become stable by filling the outer energy level. Columns 1,2,3 do this by losing 1,2 or 3 electrons and becoming positive ions. +1, +2, +3, respectively
Columns 15, 16, 17 do this by taking those electrons and becoming negative ions. -3, -2, -3. respectively.
Answer:
Option C = 1.72 mol
Explanation:
Given data:
Mass of KF = 100 g
Moles of KF = ?
Solution:
First of all we have to calculate the molar mass of KF.
Molar mass of KF = 39.0983 g/mol + 18.998403 g/mol
Molar mass of KF = 58. 0967 g/mol
Formula:
Number of moles = mass/molar mass
Number of moles = 100 g/ 58.0967 g/mol
Number of moles = 1.72 mol
The correct answer is A. Extensive, quantitative
Explanation:
A property is classified as extensive if it varies with the amount of the substance; this applies to mass, which is measured in grams or kilograms, because depending on the size of the sample the mass changes, therefore "69.2 kg" is an extensive characteristic. Besides this, quantitative characteristics or properties are those that can be measured through numbers; this also applies to mass because a specific number of grams or kilograms shows the exact mass in the substance, in this case, the value is 69.2 kg. Thus, this characteristic is both extensive and quantitative.
Given : Density of Bromine = 3.12 g/mL
Formula : Density = Mass / Volume
Part A :
Given Volume = 125 mL
Density = Mass / Volume
So, Mass = Density x Volume
= 3.12 x 125
= 390 grams
Part B :
Given mass = 85.0 gm
Density = Mass / Volume
So, Volume = Mass / Density
= 85 / 3.12
= 27.24 mL
