Answer:
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air.
Explanation:
You just look at what vertical row that silicon is, and every element that is in the same vertical row as silicon will have the same lewis dot structure...and this applyes for most elements on the periodic table of elements.
- C, Ge,Sn, Pb:
all these elements are in the same column, and therefore have the same number of valence electrons
Answer:
50 C?
Explanation:
90 - 40 = 50 So 50 degrees celsius is your answer
Answer:
I think is the last one.
Anthracite – Stage Four
Anthracite, the fourth stage in coal formation, is also known as “hard coal” because it is hard and has a high lustre. It appears to have been formed as a result of combined pressure and high temperature. Anthracite burns with a short flame and little smoke.
Answer: In real sense, all of these things could happen. But the one that would suit this question would most definitely be 4.
Explanation: