Answer:
Electrons
Explanation:
In an atom there would be three subatomic particles: Neutrons, electrons, protons. The smallest and lightest in terms of mass is electrons. This is because the nucleus is comprised of the protons and the neutrons, these have a greater mass than electrons as electrons has very little mass that can considered to be 0.
Answer: Vitamins
Explanation:
they are nutrients that are made by living things
Answer:
![\boxed {\boxed {\sf 1290 \ g \ PI_3}}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%201290%20%5C%20g%20%5C%20PI_3%7D%7D)
Explanation:
We want to convert from moles to grams, so we must use the molar mass.
<h3>1. Molar Mass</h3>
The molar mass is the mass of 1 mole of a substance. It is the same as the atomic masses on the Periodic Table, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
We are given the compound PI₃ or phosphorus triiodide. Look up the molar masses of the individual elements.
- Phosphorus (P): 30.973762 g/mol
- Iodine (I): 126.9045 g/mol
Note that there is a subscript of 3 after the I in the formula. This means there are 3 moles of iodine in 1 mole of the compound PI₃. We should multiply iodine's molar mass by 3, then add phosphorus's molar mass.
- I₃: 126.9045 * 3=380.7135 g/mol
- PI₃: 30.973762 + 380.7135 = 411.687262 g/mol
<h3>2. Convert Moles to Grams</h3>
Use the molar mass as a ratio.
![\frac {411.687262 \ g \ PI_3}{ 1 \ mol \ PI_3}](https://tex.z-dn.net/?f=%5Cfrac%20%7B411.687262%20%5C%20g%20%5C%20PI_3%7D%7B%201%20%5C%20%20mol%20%5C%20PI_3%7D)
We want to convert 3.14 moles to grams, so we multiply by that value.
![3.14 \ mol \ PI_3 *\frac {411.687262 \ g \ PI_3}{ 1 \ mol \ PI_3}](https://tex.z-dn.net/?f=3.14%20%5C%20mol%20%5C%20PI_3%20%2A%5Cfrac%20%7B411.687262%20%5C%20g%20%5C%20PI_3%7D%7B%201%20%5C%20%20mol%20%5C%20PI_3%7D)
The units of moles of PI₃ cancel.
![3.14 *\frac {411.687262 \ g \ PI_3}{ 1 }](https://tex.z-dn.net/?f=3.14%20%2A%5Cfrac%20%7B411.687262%20%5C%20g%20%5C%20PI_3%7D%7B%201%20%7D)
![1292.698 \ g\ PI_3](https://tex.z-dn.net/?f=1292.698%20%5C%20g%5C%20PI_3)
<h3>3. Round</h3>
The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we calculated, that is the tens place.
The 2 in the ones place tells us to leave the 9.
![1290 \ g \ PI_3](https://tex.z-dn.net/?f=1290%20%5C%20g%20%5C%20PI_3)
3.14 moles of phosphorous triiodide is approximately equal to <u>1290 grams of phosphorus triodide.</u>
The experimental control is the standard used as a comparison for the experimental groups.
For example, you may be trying to find out how different types of disinfectants affect bacterial growth. The control group would receive <em>no</em> disinfectant whereas the experimental groups would be the ones on which the disinfectants were tested.
Hope this makes sense!