Table salt (NaCl) is a compound. Every molecule of table salt has the same properties as every other molecule of table salt because they all have one sodium (Na) atom and one chlorine (Cl) atom. This is referred to as fixed composition.
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Answer:
The partial pressure of carbon dioxide is 22.8 mmHg
Explanation:
Dalton's Law is a gas law that relates the partial pressures of the gases in a mixture. This law says that the pressure of a gas mixture is equal to the sum of the partial pressures of all the gases present.
In this case:
Ptotal=Pnitrogen + Poxygen + Pcarbondioxide
You know that:
- Ptotal= 0.998 atm
- Pnitrogen= 0.770 atm
- Poxygen= 0.198 atm
- Pcarbondioxide= ?
Replacing:
0.998 atm=0.770 atm + 0.198 atm + Pcarbondioxide
Solving:
Pcarbondioxide= 0.998 atm - 0.770 atm - 0.198 atm
Pcarbondioxide= 0.03 atm
Now you apply the following rule of three: if 1 atm equals 760 mmHg, 0.03 atm how many mmHg equals?

Pcarbondioxide= 22.8 mmHg
<u><em>The partial pressure of carbon dioxide is 22.8 mmHg</em></u>
Answer: 
Explanation:
Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
Digits from 1 to 9 are always significant and have infinite number of significant figures.
All non-zero numbers are always significant.
All zero’s between integers are always significant.
All zero’s after the decimal point are always significant.
All zero’s preceding the first integers are never significant.
Thus
has three significant figures
The unites of measurement in a data table should be shown in the headings of some columns.
Answer:
In order to take steps by humans for controlling the change in climate.
Explanation:
It is important that scientist find out the change which occurs in the climate with the passage of time by performing experiments and also repeat the experiments in order to verify their findings. Due to these experiments, scientists also find out the reasons behind of climate change which enable us to take steps in preventing the change that occurs in the environment. it is also important for scientists to be able to explain how they know that climate has changed over time in order to explain that he is not assuming or making predictions, he has to provide evidence for his statement which is only be possible through experiments.