Answer:
False
Explanation:
The first reaction is;
NO(g) + 1/2O2(g) ---->NO2(g)
K= [NO2]/[NO] [ O2]^1/2
The second reaction is;
2NO(g) + O2(g) ---->2NO2(g)
K'= [NO2]^2/[NO]^2 [O2]
It now follows that;
K'= K^2
Hence the statement in the question is false
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:
An alcohol thermometer can measure the freezing point of a liquid that freezes at −80 °C.
Explanation:
A thermometer is a device used to measure temperature. A thermometer must contain a thermometric substance. A thermometric substance is any substance having a particular physical property that changes with temperature.
For all liquid-in-glass thermometers, the property that changes with change in temperature is the height of the liquid. There are two kinds of liquid-in-glass thermometers; mercury-in-glass thermometer and alcohol-in-glass thermometer.
Alcohol-in-glass thermometer measures very low temperatures up to as low as -115°C. If it measures such a low temperature, then it can efficiently measure -80°C hence the answer.
Alcohol-in-glass thermometers have a narrower temperature range than mercury-in-glass thermometer. The later is well adapter for the measurement bof higher tempetures up to 357°C.
Answer:
30 cm³
Explanation:
Step 1: Given data
- Density of aluminum (ρ): 2.7 g/cm³
- Mass of aluminum (m): 81 g
- Volume occupied by aluminum (V): ?
Step 2: Calculate the volume occupied by aluminum
The density of aluminum is equal to its mass divided by its volume.
ρ = m/V
V = m/ρ
V = 81 g / 2.7 g/cm³
V = 30 cm³
Lowest is Hydrogen highest is <span>Beryllium
-HOPE THIS HELPED </span>