I *think* through weathering and erosion. Hope this helped
Answer: 4.5 moles of 
can be made from complete reaction of 3.0 moles of Al.
Explanation:
The given reaction equation is as follows.
This shows that 2 moles of Al reacts with 6 moles of HCl. So, the amount of HCl required to react with 1 mole Al is three times the amount of HCl.
Therefore, 3 moles of Al will react with 9 moles of HCl to give 3 moles of 
and 
moles of .
The reaction equation now will be as follows.
The moles can also be written as 4.5 moles.
Thus, we can conclude that 4.5 moles of can be made from complete reaction of 3.0 moles of Al.
Answer:
b.) Br and Br
Explanation:
A covalent bond occurs when electrons are shared between two atoms causing them to form a bond.
A "pure" covalent bond refers to a nonpolar covalent bond. In these bonds, the electrons are shared equally between two atoms as a result of the absence of an (or very small) electronegativity difference. The purest covalent bond would therefore be between two atoms of the same electronegativity. Two bromines (Br) have the same electronegativity, thus making it the purest covalent bond.
Polar covalent bonds occur when electrons are shared unequally between two atoms. There is a larger electronegativity difference between the two atoms, but not large enough to classify the bonds as ionic. In this case, a.) and c.) are polar covalent bonds and d.) is an ionic bond.
Answer:
Dolphins use a method called echolocation to detect things such as obstacles and prey in the water. If a dolphin swimming in seawater at 25°C sends a 220-dB click with a frequency of 120.0 Hz, and then detects the reflection of the click exactly one-twentieth of a second later, approximately how far away is the object?
Answer:
Calcium cyanamide
Explanation:
I think it has to be calcium cyanide, because of the cyanamide ion (CN).
