Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get
Therefore, the time required for decay is, 84 days.
Answer:
1/360
Explanation:
let x = liters
molarity=moles of solute/liters of solution, 7.2=0.02/x or 7.2=(1/50)(1/x), 7.2(50)=(1/x), 360(x)=1, x=1/360
The correct answer is B. Water that has condensed and formed water droplets on the ground, grass, and other outdoor objects is known as dew. It is water formed due to condensation in early morning or evening. It is formed when the temperature of the objects reach below the dew point of the air around.
Answer:
The atomic mass of nitrogen is
<h2>
14.0067 u</h2>
<h2>
<em>You learn more from failure than from success</em></h2>
Answer:
Explanation:
Noise pollution occurs when we have a house which is more than 65 decibels. The effects of noise pollution include physical effects which can be respiratory agitation, headaches, high blood pressure, etc.
Another effect is the psychological effect such as depression, anxiety, fatigue etc. Stress can also lead to sleep disorders and lack of concentration.
The ways to reduce noise pollution are:
1. Using awareness campaign: People should be told about the harmful effects of noise. This will be vital in reducing noise.
2. Government control: Government can play their role by telling those who doesn't adhere to laid out rules regarding noise to pay a fine. Anyone found wanting should pay a fine.
