Because 25% is half of 0.5 and the half life of is given as 5,715, the time it takes to reach this amount should just be double the half life: 11430 years.
However, in other cases the problem may not have easy numbers, so below is a more mathematical approach.
The half life formula is .
Solving for t gives:
Given information:
Plug in given values and solve for t.
With correct significant figures, this would be 11000 years.
Answer:
Barium Cyanide, Ba(CN)2, is formed by passing anhydrous hydrocyanic acid over cooled barium hydroxide crystals, and dissolves in the water of crystallisation of the hydrated baryta. With anhydrous barium oxide or hydroxide too vigorous a reaction takes place and the cyanide is decomposed.
Answer:
True
Explanation:
The complete question is:
<u><em>"A reaction contains two reactants, A and B. If A is doubled, there will be a greater number of effective collisions between reactants. TRUE FALSE"</em></u>
Collision Theory indicates that chemical reactions take place because molecules, atoms or ions collide with each other.
Furthermore, the molecules must collide effectively, that is, not all reagent collisions lead to product formation. Effective shock means that the reagent molecules have enough kinetic energy at the time of the shock for their bonds to break and product bonds to form. In addition, the molecules of the reagents must be properly oriented for the reaction to take place.
As the concentration increases, the number of shocks increases. In other words, by increasing the concentration of the reactants, the probability of collision between their molecules increases, and therefore the number of effective collisions.So the statement is true-
Since the volume of both the lead and the sand is 1.0-cm3, the exactly 1.0-cm3 of water is displaced in both cases.
<h3>How does the volumes compare?</h3>
The commonest way to measure the volume of a substance is by the displacement method. In this method, the substance is added into water and the volume of the water displaced is measured.
Let us note that the volume of water displaced is equal to the volume of the object. Since the volume of both the lead and the sand is 1.0-cm3, the exactly 1.0-cm3 of water is displaced in both cases.
Learn more about volume:brainly.com/question/1578538
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