Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
Answer:
Carbonic acid could be formed.
Explanation:
Hello,
Based on her claim, it would be a really useful strategy to prevent global warming, nevertheless, there would be a problem if a increasing amount of carbon dioxide is not buried at the bottom of the ocean yet it flows freely along the sea and probably reacting with the water, causing carbonic acid to be formed and subsequently cutting back the sea's pH (increasing its acidity).
It would be useful, but a constant monitoring of the sea's pH must be needed because this could cause some species to be affected not only by the temperature but for the acid pH as well.
Best regards.
Answer:
The answer is B. False
Explanation:
The ratio of sizes between the ionic radii of cations and anions in a cell influences the manner of packing for that cell thereby predicting the possible cation/anion coordination number in any compound and establishing the structure of ionic solids.
The volume increases when the balloon temperature increases.
<u>Explanation:</u>
-10 F is converted into Kelvin as 249 K.
0°C is nothing but 0+ 273 = 273 K
And the room temperature is 25°C which is converted into Kelvin as 273 + 25 = 298 K.
249 K is below room temperature.
As per the Charles' law volume and temperature are directly proportional to each other, when the pressure of the gas remains constant.
V ∝ T
As the balloon temperature increases, the volume also increases.
Answer:
The answer is
Explanation:
The energy of a quantum of light can be found by using the formula
<h3>E = hf</h3>
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
f = 4.31 × 10¹⁴ Hz
We have
E = 4.31 × 10¹⁴ × 6.626 × 10-³⁴
We have the final answer as
Hope this helps you
