Answer:
not sure if this is the right way to answer this question but PbS is Phosphate-buffered saline (i think)
Explanation:
(a)- Time
(b)- Heat produced(i guess)
(c)- Material
this is what I think, hope it helps
Answer: Oxygen usually forms two covalent bonds or a covalent double bond.
Explanation:
A covalent bond is formed by the sharing of 2 electrons, 1 electron from each of the atoms sharing their electrons.
The number of bonds that each element can form depends on the number of valence (outermost) electrons it contains. Oxygen has 6 electrons in its valence shell and needs 2 more electrons thereby forming a double bond.
D. Sublimation is a solid turning directly into a gas
