On June 21, as seen from the North pole ...
-- the sun has been up, and it's been light outside,
for the past three months ... ever since March 21 .
-- The sun won't set, and it won't be dark outside,
for another three months ... until September 21.
-- Here at the North pole, it stays daylight for six months straight.
Today, on June 21, we're exactly halfway through the period of
continuous daylight.
Answer:
Both <u>elements </u>and <u>compounds</u> can be classifies as pure substances because they have distinct properties and composition.
Explanation:
Elements and compounds are considered as pure substances because both are always formed form are have same kind of atoms.
For example,
Carbon dioxide is compound. It always consist of one carbon atom and two oxygen atoms.
Water is compound it always have same kind of atoms two hydrogen and one oxygen that's why compounds are considered as pure substances.
Same is the case with elements. For example,
Hydrogen is element and it always consist of H atoms.
Iron is another element and it always have iron atoms.
So elements and compounds are always consist of same substances that's why they are considered as pure.
Answer:
We identify nucleic acid strand orientation on the basis of important chemical functional groups. These are the <u>phosphate</u> group attached to the 5' carbon atom of the sugar portion of a nucleotide and the <u>hydroxyl</u> group attached to the <u>3'</u> carbon atom
Explanation:
Nucleic acids are polymers formed by a phosphate group, a sugar (ribose in RNA and deoxyribose in DNA) and a nitrogenous base. In the chain, the phosphate groups are linked to the 5'-carbon and 3'-carbon of the ribose (or deoxyribose) and the nitrogenous base is linked to the 2-carbon. Based on this structure, the nucleic acid chain orientation is identified as the 5'-end (the free phosphate group linked to 5'-carbon of the sugar) and the 3'-end (the free hydroxyl group in the sugar in 3' position).
The energy of the wave does not move through anything
