Answer:

Explanation:
1 mole of any substance contains the same number of particles. The particles can vary (atoms, molecules, formula units), but there are always 6.022*10²³ particles. In this case, the particles are formula units of potassium nitrate or KNO₃.
Let's create a ratio.

Since we are trying to find the formula units in 0.250 moles, we multiply by that number.

The units of moles of potassium nitrate cancel.

The denominator of 1 can be ignored, so we can make a simple multiplication problem.


If we round to the nearest tenth, the 0 in the hundredth place tells us to leave the 5 in the tenth place.

0.250 moles of potassium nitrate is approximately equal to 1.5*10²³ formula units of potassium nitrate and choice B is correct.
Answer:
107.8682 u
Explanation:
Well Silver has an atomic mass of aproximately 107.9. 1 mole of silver atoms = 107.9g and there are 6.02x10^23 atoms in one mole. Therefore to find mass of one atom you should divide the mass by Avodgadro's constant to find the mass of one atom because they all have an even distribution of mass.
The average atomic mass of the element takes the variations of the number of neutrons into account, and tells you the average mass per atom in a typical sample of that element. For example, the element silver (Ag) has two naturally occurring isotopes: Ag-107 and Ag-109 (or 107Ag and 109Ag).
a.The gas pressure will decrease.
Explanation:
If in a rigid container, the amount of gas particles and volume of the container is held constant, the pressure will decrease if the temperature is reduced.
- Gases are highly random particles and they require a high amount of kinetic energy to be in their state of matter.
- In a condition where volume of container is fixed, the amount of gas particles is fixed and the temperature reduced, the kinetic energy of the gas particles will directly reduce.
- The kinetic energy of gases is directly related to temperature.
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kinetic theory brainly.com/question/9924094
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