Answer:
17. The iron metal is oxidized to form the iron oxide known as rust.
19.A saturated solution will not dissolve any more solute and any extra solute added will simply stay as it is, without dissolving. An unsaturated solution has less solute than its solubility and hence can still add more solute, till it reaches the saturation level.
26 An Overflowing Population. The swelling American population played a large part in the decision Americans made to head, The Government Opens Up New Land. The American government itself encouraged its citizens to move west
32. The periodic table was first assembled in 1869 by a Russian chemist named Dmitri Mendeleev. He came up with a way of organizing the elements that were known at the time, arranged them in order of atomic weight, and then grouped them into rows and columns based on their chemical and physical properties. Here is a unique "Mayan" format Periodic Table. Elements in the same group are those that are in a single vertical line from top to bottom. They have the most in common between the two directions. They share the same number of electrons in their valence subshells.
Explanation:
Answer:
3,964 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 the element is 5,730 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/(5,730 years) = 1.21 x 10⁻⁴ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 1.21 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of the sample ([A₀] = 100%).
[A] is the remaining concentration of the sample ([A] = 61.9%).
∴ t = (1/k) ln([A₀]/[A]) = (1/1.21 x 10⁻⁴ year⁻¹) ln(100%/61.9%) = 3,964 years.
The answer is (3) methods to achieve racial equality.
Both Du Bois and Washington had different views on how to promote equality, Du Bois emphasized education and immediate political equality while Washington was more concerned with economic equality in industrial and agriculture
The formula for kinetic energy is KE=1/2(mv²). Since both mass and velocity are multiplied by each other, particle with a larger mass needs to be moving slower than a particle with less mass if both have the same kinetic energy. You can think of it as 2KE/m=v² or 2KE/v²=m, If you increase the mass the velocity needs to decrease to keep the same KE value.
I hope this helps. Let me know in the comments if anything is unclear.
Alkina metals all have the similar proteries
