Answer:
yes
Explanation:
The cell theory states that all biological organisms are composed of cells; cells are the unit of life and all life come from preexisting life. The cell theory is so established today that it forms one of the unifying principles of biology.
This is genetic engineering.
I hope this helps!
Cheer,s July.
Answer:
The answer to your question is 1.2 moles of copper
Explanation:
Data
mass of copper = 75 g
moles = ?
Process
1.- Look in the periodic table for the atomic mass of copper.
Atomic mass = 63.55 g/mol
2.- Use proportions to determine the moles of copper in 75 g
63.55 g of copper -------------------- 1 mol
75 g of copper -------------------- x
Use cross multiplication
x = (75 x 1) / 63.55
x = 75 / 63.55
x = 1.18 moles ≈ 1.2 moles of copper
The flame test is commonly used to identify different metal ions by how they get excited in the presence of a flame.
Typically a nichrome wire is dipped in a solution of metal cations and then presented to a flame. The flame emits a different color than normal, depending on the type of metal cation. Each metal ion gets excited by the flame and as the electrons change energy levels they emit a photon of light, thus changing the color. Since each metal cation has unique energy levels, the colors differ depend on the metal cation.
I hope this helps.
Answer:
0.147 billion years = 147.35 million years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of Potassium-40 is 1.25 billion years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(1.25 billion years) = 0.8 billion year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
<em></em>
where, k is the rate constant of the reaction (k = 0.8 billion year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of (Potassium-40) ([A₀] = 100%).
[A] is the remaining concentration of (Potassium-40) ([A] = 88.88%).
- At the time needed to be determined:
<em>8 times as many potassium-40 atoms as argon-40 atoms. Assume the argon-40 only comes from radioactive decay.</em>
- If we start with 100% Potassium-40:
∴ The remaining concentration of Potassium-40 ([A] = 88.88%).
and that of argon-40 produced from potassium-40 decayed = 11.11%.
- That the ratio of (remaining Potassium-40) to (argon-40 produced from potassium-40 decayed) is (8: 1).
∴ t = (1/k) ln([A₀]/[A]) = (1/0.8 billion year⁻¹) ln(100%/88.88%) = 0.147 billion years = 147.35 million years.
