Option 2, Br. I'll go over why all other three options are incorrect.
Option 1 - Krypton is a Noble gas, and so it doesn't need to accept electrons since it has an octet.
Option 3 and 4 - Both Calcium and Barium are alkaline earth metals, and give away electrons, since they only have 2.
-T.B.
Answer:
750g of Aluminum
Assuming 8.6 cm lenth is the height of the cylinder. The volume of a cylinder is: V =
*r^2*h
V = 3.14cm x 10.24cm x 3.6cm
V = 280cm^3
Now density = mass/volume
2.7g/cm^3 = mass/280cm^3
2.7g/cm^3 x 280cm^3 = mass/<u>280cm^3</u> x <u>280cm^3</u>
= 750g of Aluminum
This problem is providing the atmospheric pressure at 2000 m altitude which is 560. mmHg and asks for this pressure in units of atmospheres, which after doing the calculations, the result is 0.737atm.
<h3>Atmospheric pressure:</h3><h3 />
In this case, we can firstly define the concept of atmospheric pressure, also known as barometric pressure, as that pressure exerted by a column of air over a specific point in space at a defined altitude.
<h3>Units conversion in pressure:</h3><h3 />
In order to get the correct conversion, we use the following equivalence statement relating mercury millimeters and atmospheres:
760 mmHg = 1 atm
Hence, the required conversion turns out to be:

Learn more about atmospheric pressure: brainly.com/question/1393320
Answer:
The element formed when a radioactive element undergoes radioactive decay. The latter is called the parent. The daughter may or may not be radioactive.
Explanation:
hope this helps
Well on a side note, a mole in chemistry is also the same as a Liter. A mole however, is the mass of an element,or compound. 1 mol of O would be 15.9994 grams/mol. It can also be represented as 6.022*10 to the 23 power. (1 mol of Carbon-12 atoms)