Isotopes are atoms of the same element that have different masses. The relative atomic mass (am) is a weighted average that takes into account the abundance of each isotope. We can calculate the relative atomic mass using the following expression.

where,
- abi: percent abundance of each isotope
For Gallium,
[1]
where "x" and "y" are the unknown abundances.
We also know that the sum of both abundances must be 100%.
x + y = 100
y = 100 - x [2]
If we replace [2] in [1], we get

Then, in [2]
y = 100 - x = 100 - 20.5 = 79.5
In conclusion, Ga-69 has an abundance of 20.5% and Ga-71 has an abundance of 79.5%.
You can learn more about isotopes in: brainly.com/question/21536220?referrer=searchResults
Answer:
A-Pacific Ocean
B-Arctic Ocean
C-Atlantic Ocean
D-Indian Ocean
E-Southern Ocean
Explanation:
got it right on edge 2020!!
Answer:
Here's what I get
Explanation:
A. Initial observation
Gary's shell had slime and an odour.
B. Independent variable
The independent variable is the one that the experimenter changes.
There are two independent variables: the rubbing with seaweed and the drinking of Dr. Kelp.
C. The dependent variable
The dependent variable is the amount of slime and odour.
D. The conclusion
Sponge Bob can conclude that rubbing the shell with seaweed and drinking Dr. Kelp removes the slime and odour.
However, this was a poorly designed experiment. He doesn't know if it is the seaweed or the Dr. Kelp that gives the result or if he must use both together. He should change only one independent variable at a time.
Answer:
Freezing
Explanation:
When a liquid goes to a solid, this process is called freezing.
Answer:
DUPLET RULE: The tendency of an atom to acquire an outer most shell of two electrons is called duplet rule. OCTET RULE: The tendency of an atom to acquire an outermost shell of eight electrons is called the octet rule.