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 study of plants, plant life cycles, photosynthesis, plant parts, etc. is under botany (study of plants).
In order to answer this question, the units of volume must be consistent. In this problem, we decide the unit m3 to be uniform. Option A is equal to 12 m3, option b is equal to 1.2x10^8/100^3 or 120 m3. Option C is 2.0 x10^4/ 10^3 or 20 m3. Option D is 1.2x10^8/ 1000^3 or 0.12 m3. The greatest volume is option b. 120 m3.
Electronegativity of boron is the highest in the group and it will form covalent bonds in all his combinations.
The rest of the group will form bonds with intermediate nature between covalent and ions bods in their respective compounds, with thallium (Tl) behaving most close to a metal.
Moreover boron have a very high melting points (around 2200 °C) while in the boron cristal the chemical bonds are directed in space, similar with carbon suggesting his nature as a non-metal.
Other elements form the group Al, Ga, In, Tl have lower melting points 660, 30, 157 and 304 °C, respectively. Also in the elemental state, they have metallic characteristics: metalic luster, ductility, high electrical and thermal conductivity.
Equation for half-lives:
Nt = No x (1/2)^n
No = initial amount
Nt = final amount after t years
n = number of half lives = t/(single half-life)
t = years
Nt = 3/12 = 0.25
No = 12/12 = 1.00
n = t/(24400)
3/12 = (12/12) x (0.5)^(t/24400)
(0.25) = 1.00 x (0.5)^(t/24400)
0.25/1.00 = 0.5^(t/24400)
ln(0.25) = ln(0.5^(t/24400))
ln(0.25) = (t/24400)*ln(0.5)
ln(0.25)/ln(0.5) = (t/24400)
2 = t/24400
2*24400 = t
t = 48800 yrs
answer is <u>t = 48,800 yrs</u>
