It is B. Thank you later please and do good on the test!
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: d. have the silicon-oxygen tetrahedron as their structural unit.
Explanation:
Silicates are anions that have both Oxygen and Silicon as the basis of their structure. These two form a tetrahedron type structure that enable them to be useful for a whole lot of things.
Silicates are very abundant on Earth as they comprise around 95% of the Earth's crust as well as the upper mantle which explains why they are mostly found in igneous rocks.
Asexual
Pro:
1. inexpensive to make offspring (usually make a lot at a time and not invest a lot of time in raising them).
2. Do not need a mate to reproduce.
3. Can rapidly expand a population
Con:
1. genetically identical- prone to extinction because once a parasite has evolved to attack a specific genotype, it can kill them all.
2. Lineages usually don't last longer than a couple thousand years
Sexual:
Pros:
1. Genetically unique- so more likely to create a "successful" offspring
2. Lineages more likely to last hundreds of thousands of years
Cons:
1. More effort into creating offspring- require more parental effort
2. STD's- easily to pass
3. need to find a mate or else won't be successful as an organism.
Hope this helps you.
Answer:
a) Mo the electron configuration: 42Mo: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d4
Mo3+ - is Paramagnetic
b) Au - [Xe] 4f14 5d10 6s1
For Au+ is not paramagnetic
c) Mn - [Ar] 3d5 4s2
Mn2+ is paramagnetic
d)Hf -[Xe] 4f¹⁴ 5d² 6s²
Hf2+ is not paramagnetic
Explanation:
An atom becomes positively charged when it looses an electron.
Diamagnetism in atom occurs whenever two electrons in an orbital paired equalises with a total spin of 0.
Paramagnetism in atom occurs whenever at least one orbital of an atom has a net spin of electron. That is a paramagnetic electron is just an unpaired electron in the atom.
Here is a twist even if an atom have ten diamagnetic electrons, the presence of at least one paramagnetic electron, makes it to be considered as a paramagnetic atom.
Simply put paramagnetic elements are one that have unpaired electrons, whereas diamagnetic elements do have paired electron.