D) refracted
because , the light changes direction.. causing the penny to look bigger than it is.
Answer:
.
Explanation:
Electrons are conserved in a chemical equation.
The superscript of indicates that each of these ions carries a charge of . That corresponds to the shortage of one electron for each ion.
Similarly, the superscript on each ion indicates a shortage of three electrons per such ion.
Assume that the coefficient of (among the reactants) is , and that the coefficient of (among the reactants) is .
.
There would thus be silver () atoms and aluminum () atoms on either side of the equation. Hence, the coefficient for and would be and , respectively.
.
The ions on the left-hand side of the equation would correspond to the shortage of electrons. On the other hand, the ions on the right-hand side of this equation would correspond to the shortage of electrons.
Just like atoms, electrons are also conserved in a chemical reaction. Therefore, if the left-hand side has a shortage of electrons, the right-hand side should also be electrons short of being neutral. On the other hand, it is already shown that the right-hand side would have a shortage of electrons. These two expressions should have the same value. Therefore, .
The smallest integer and that could satisfy this relation are and . The equation becomes:
.
<h3>
Answer:</h3>
42960 years
<h3>
Explanation:</h3>
<u>We are given;</u>
- Remaining mass of C-14 in a bone is 0.3125 g
- Original mass of C-14 on the bone is 80.0 g
- Half life of C-14 is 5370 years
We are required to determine the age of the bone;
- Remaining mass = Original mass × 0.5^n , where n is the number of half lives.
Therefore;
0.3125 g = 80.0 g × 0.5^n
3.90625 × 10^-3 = 0.5^n
- Introducing logarithm on both sides;
log 3.90625 × 10^-3 = n log 0.5
Solving for n
n = log 3.90625 × 10^-3 ÷ log 0.5
= 8
- Therefore, the number of half lives is 8
- But, 1 half life is 5370 years
- Therefore;
Age of the rock = 5370 years × 8
= 42960 years
Thus, the bone is 42960 years old
Window cleaner is ammonia dissolved in water. This is an example of a _______.