the surface temp of main sequence star increase as diameter increases
The periodic law is a law relating the properties of the element with their
atomic numbers.
The element is <u>potassium, K</u>.
Reason:
By atomic mass, potassium is 39.10 g, while argon is 39.10 g.
Going by the atomic mass alone, potassium should come before argon in
the periodic table and therefore should be an halogen and not an alkali
metal.
However, the number of protons in the potassium is 19, and therefore larger
than the number of protons in argon, which is argon.
Therefore, the element is <u>potassium, K</u>.
Learn more about the periodic law here:
brainly.com/question/2207821
Answer:
Density of the He atom = 12.69 g/cm³
Explanation:
From the information given:
Since 1 mole of an atom = 6.022x 10²³ atoms)
1 atom of He = 

The volume can be determined as folows:
since the diameter of the He atom is approximately 0.10 nm
the radius of the He =
= 0.05 nm
Converting it into cm, we have:


Assuming that it is a sphere, the volume of a sphere is
= 
= 
= 
Finally, the density can be calcuated by using the formula :


D = 12.69 g/cm³
Density of the He atom = 12.69 g/cm³
Answer:
Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Although water is the most abundant substance on earth, it is rarely found naturally in its pure form. Most of the time, pure water has to be created. Pure water is called distilled water or deionized water.