Answer: b} The exact time when an individual atom will decay can be accurately predicted.
c} After each half-life, the amount of radioactive material is reduced by half.
Explanation:
All radioactive decay follows first order kinetics.
Rate law expression for first order kinetics is given by:
where,
k = rate constant
t = time taken for decay process
a = initial amount of the reactant
a - x = amount left after decay process
Expression for calculating half life, which is the time taken by the half of the reactants to decompose is:
Answer:
Na.
Explanation:
- The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent).
- An oxidizing agent, or oxidant, gains electrons and is reduced in a chemical reaction. Also known as the electron acceptor, the oxidizing agent is normally in one of its higher possible oxidation states because it will gain electrons and be reduced.
- A reducing agent (also called a reductant or reducer) is an element (such as calcium) or compound that loses (or "donates") an electron to another chemical species in a redox chemical reaction.
<em>2Na + S → Na₂S.</em>
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Na is oxidized to Na⁺ in (Na₂S) (loses 1 electron). "reducing agent".
S is reduced to S²⁻ in (Na₂S) (gains 2 electrons). "oxidizing agent".
To solve this problem we just need to use the rule of three:
150g..................395.1J
450g................xJ
x = 450*395.1/150 = 1185,3J
450.0 g of the substance completely reacted with oxygen will produce 1.1853 kJ(<span>kiloJoule</span>)
<span>1.18 x 3 = 3.55 </span>
find ratio of F to F in each compound
. according to law of multiple proportions that the masses of one element which combine with a fixed mass of the second element are in a ratio of whole numbers.
now F is "one element" and S has "fixed mass",
the ratio of F6 to Fx = 3:1
<span>thats why x= 2
there is less F in SFx
the ratio is 3:1.
dividing 6 by 3 and you get 2</span>
