<u>Answer:</u> The percentage abundance of and isotopes are 75.77% and 24.23% respectively
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
Let the fractional abundance of isotope be 'x'. So, fractional abundance of isotope will be '1 - x'
- <u>For isotope:</u>
Mass of isotope = 62.9396 amu
Fractional abundance of isotope = x
- <u>For isotope:</u>
Mass of isotope = 64.9278 amu
Fractional abundance of isotope = 1 - x
- Average atomic mass of copper = 63.546 amu
Putting values in equation 1, we get:
Percentage abundance of isotope =
Percentage abundance of isotope =
Hence, the percentage abundance of and isotopes are 69.50% and 30.50% respectively.
<span>From the given balanced chemical reaction, it can be seen that each aluminum atom gains loses 3 electrons. Also, each copper atoms gains 2 electrons. The choice that would best give us the described scenario above is choice number 2. That is Each Al loses 3e- and each Cu gains 2e-. </span>
Answer:
The options to this question are incomplete. The remaining two options are:
C. Water expands and becomes less dense when it freezes.
D. Water contracts and becomes less dense when it freezes.
The answer is C. Water expands and becomes less dense when it freezes.
Explanation:
Water is a chemical compound that exists in the three states of matter viz: solid as ICE, gas as vapour and liquid as WATER. However, due to the DENSITY properties of each state, ice floats on water. Ice is less dense than water.
When liquid water freezes, it's particles expands i.e increases in volume. Hence, it becomes less dense than water. This causes an iceberg to float on water because it has a lesser density compared to the liquid water caused by an expansion of its particles.