Answer:
A. Convex lens.
Explanation:
A convex lens causes light rays to meet at a focal point unlike concave, which lights rays spread out.
Answer:
The Earth absorbs most of the energy reaching its surface
Explanation:
a small fraction is reflected. In total approximately 70% of incoming radiation is absorbed by the atmosphere and the Earth's surface while around 30% is reflected back to space and does not heat the surface.
Hydrogen bonds.
________________
Answer:
MnO- Manganese Oxide
Explanation:
Empirical formula: This is the formula that shows the ratio of elements
present in a
compound.
How to determine Empirical formula
1. First arrange the symbols of the elements present in the compound
alphabetically to determine the real empirical formula. Although, there
are exceptions to this rule, E.g H2So4
2. Divide the percentage composition by the mass number.
3. Then divide through by the smallest number.
4. The resulting answer is the ratio attached to the elements present in
a compound.
Mn O
% composition 72.1 27.9
Divide by mass number 54.94 16
1.31 1.74
Divide by the smallest number 1.31 1.31
1 1.3
The resulting ratio is 1:1
Hence the Empirical formula is MnO, Manganese oxide
Answer:
The pH of the solution is 7, 52
Explanation:
The pH gives us an idea of the acidity or alkalinity of a solution. Is calculated:
pH = -log (H +)
pH= -log ( 3x10-8)= <em>7, 52</em>
