D. All of the answers are true
First, we need to be aware that our blood is also a form of liquid.
So, when the astronaut is placed in within the environment that has decreased pressure, the temperature inside the astronaut's body will definitely increase but it won't cause the boiling effect like in water (it won't even break the arteries). But it could endanger the astronaut's life because it makes the blood unable to circulate properly due to unstable blood pressure
Answer:

Explanation:
(a) Balanced equation
Cu + 2AgNO₃ ⟶ Cu(NO₃)₂+ 2Ag
(b) Calculation
You want to convert atoms of Cu to atoms of Ag.
The atomic ratio is ratio is 2 atoms Ag:1 atom Cu

Answer: 75%
Explanation:
The following information can be gotten from the question:
Waste = 70kg
Theoretical yield = 280kg
Therefore, the actual yield will be the difference between the theoretical yield and the waste which will be:
= 280kg - 70kg = 210kg
The percent yield will now be:
= Actual yield / Theoretical yield × 100
= 210/280 × 100
= 3/4 × 100
= 75%