False. Eyeglasses do not cover all around the eye however safety goggles do
Answer:
2HNO3 +Na2CO3 → CO2 + H2O + 2NaNO3
Answer:
The amount of drug left in his body at 7:00 pm is 315.7 mg.
Explanation:
First, we need to find the amount of drug in the body at 90 min by using the exponential decay equation:

Where:
λ: is the decay constant = 
: is the half-life of the drug = 3.5 h
N(t): is the quantity of the drug at time t
N₀: is the initial quantity
After 90 min and before he takes the other 200 mg pill, we have:

Now, at 7:00 pm we have:

Therefore, the amount of drug left in his body at 7:00 pm is 315.7 mg (from an initial amount of 400 mg).
I hope it helps you!
Answer: The answer is C. A mercury thermometer is better to measure very small changes in temperature.
Explanation:
i took this quiz and this is the answer .
A) A mercury thermometer can measure the freezing point of a liquid that freezes at −80 °C.
B) An alcohol thermometer can measure the boiling point of a liquid that boils at 80 °C.
C) A mercury thermometer is better to measure very small changes in temperature.
D) An alcohol thermometer is better to measure the boiling points of colorless liquids.