Answer:
- <u><em>3.30 × 10³ years</em></u>
Explanation:
1) <u>Carbon-14 disintegration rate of a young (alive) tree</u>: 0.266 per second per gram.
2)<u> Carbon-14 disintegration rate of a wood sample prepeared from an object recovered at an archaelogical excavation (dead matter):</u> 0.178 per second per gram.
3) <u>Ratio of decay</u>: A/A₀ = 0.178 / 0.266 = 0.669
4) <u>Half-life equation</u>: A/A₀ = (1/2)ⁿ, where n is the number of half-lives since the object died.
5) <u>Substitute and solve for n</u>:
That means that 0.578 half-life has elapsed since the wood with which the object was created was dead matter.
6) <u>Convert number of half-lives to years</u>:
- 0.578 half-life × 5715 years/half-life = 3,303 years = 3.30 × 10³ years.
Answer: D
Explanation: The Eukarya differ from the Archea and Bacteria in that their cells are eukaryotic, meaning they contain a membrane enclosed nucleus and other membrane enclosed organelles.
<span>Radium and Polonium were named in honor of Marie Curie.
SO yeh true
Hope this helps!
:)
</span>
4 m/s^2
I hope this helps!
Answer:
1.21 g of Tris
Explanation:
Our solution if made of a solute named Tris
Molecular weight of Tris is 121 g/mol
[Tris] = 100 mM
This is the concentration of solution:
(100 mmoles of Tris in 1 mL of solution) . 1000
Notice that mM = M . 1000 We convert from mM to M
100 mM . 1 M / 1000 mM = 0.1 M
M = molarity (moles of solute in 1 L of solution, or mmoles of solute in 1 mL of solution). Let's determine the mmoles of Tris
0.1 M = mmoles of Tris / 100 mL
mmoles of Tris = 100 mL . 0.1 M → 10 mmoles
We convert mmoles to moles → 10 mmol . 1mol / 1000mmoles = 0.010 mol
And now we determine the mass of solute, by molecular weight
0.010 mol . 121 g /mol = 1.21 g
