Question 2(multiple choice worth 3 points)
(07.05 mc)

the table shows the concentration of a reactant in the reaction mixture over a period of time.

reactant concentration
time concentration
0 s 1.8 m
210 s 1.2 m
450 s 0.8 m
580 s 0.6 m
720 s 0.4 m

what is the average rate of the reaction over the first 580 seconds?
1.6 × 10−3
1.9 × 10−3
2.0 × 10−3
2.2 × 10−3

2.0 x 10⁻³ M/s.

Explanation:

The rate of the reaction = - Δ[reactants]/Δt = - [(0.6 M - 1.8 M)]/(580 s - 0 s) = 2.069 x 10⁻³ M/s.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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