Answer:
20619.4793 years
Explanation:
The half life of carbon-14 = 5730 years
The formula for the half life for a first order kinetic reaction is:
Where,
is the half life
k is the rate constant.
Thus rate constant is:
5730 years=ln(2)/k
k = 1.21×10⁻⁴ years ⁻¹
Using integrated rate law as:
Where,
is the concentration at time t
is the initial concentration
Given that the final concentration contains 8.25 % of the original quantity which means that:
So,
ln(.0825)= -1.21×10⁻⁴×t
<u>
t = 20619.4793 years</u>
<u></u>
Your answer is the last option, the explosion of fireworks. This is because all of the other options are physical changes because they don't change the substance, they only affect it in some way. However the explosion of a firework clearly changes a substance inside the initial 'rocket' into fireworks.
I hope this helps!
Mixtures can be separated by physical means because they are physically combined
It’s either A or C sorry I can’t help more
Answer:
Explanation:
Equilibrium is the state in which the resultant of all forces acting on an object is zero. This implies that the object do not rotate or move, but well balanced at a point. Equilibrium can either be dynamic or static.
When two unbalanced forces act on an object, the object move in the direction of the greater force. This effect nullifies equilibrium of the object.
i. Tim versus Elena and Anne - Unbalanced balanced
⇒ 70 - (100 + 30) = -60N
ii. Elena versus Tim and Anne - Balanced
⇒ 100 - (70 + 30) = 0N
iii. Anne versus Tim and Elena - Unbalanced
⇒ 30 - (70 + 100) = -140N
