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.
Skeletal Equation
Ba(NO3)2 + KCl = BaCl2+ KNO3
Balanced equation
Ba(NO3)2 + 2KCl = BaCl2 + 2KNO3
Answer:
A. The lens spreads light.
Explanation:
The convex lens will converge the light that passes through it. The direction of light will be bend to be closer to the middle point. This is the lens used for the eyeglass that treat people with hypermetropia. That is why the convex lens also called a converging lens or a plus lens. The strength of the convex lens depends on its focal length, index of the material used, and the radius of curvature.
For the first question, the correct answer would be 44.51 kJ. It is calculated by multiplying the amount of the substance in moles by the heat of the solution. For the second question, the correct answer would be a catalyst causes <span>a lowering the activation energy barrier.</span>
