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iren [92.7K]
2 years ago
7

Complete the nuclear equation 42 K → 0 e 19____-1

Chemistry
1 answer:
kenny6666 [7]2 years ago
5 0

Answer:

42 19 K→42 20 Ca+e−

Explanation:

Naturally-occurring potassium atoms have a weighted average atomic mass of 39.10 (as seen on most modern versions of the periodic table.) Each potassium atom contains 19 protons p+ and thus an average potassium atom contains about 39.10−19≈20 neutrons n0.

This particular isotope of potassium-42 contains 42 nucleons (i.e., protons and neutrons, combined;) Like other isotopes of potassium 19 out of these nucleons are protons; the rest 42−19=23 are therefore neutrons.

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Which statement is always true about conversation of matter?
Firlakuza [10]

Answer:

The mass of a system does not change during a chemical reaction

Explanation:

Correct Answers

8 0
2 years ago
How many grams are in 3.14 moles of PI₃?
OverLord2011 [107]

Answer:

\boxed {\boxed {\sf 1290 \ g \ PI_3}}

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}

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}

The units of moles of PI₃ cancel.

3.14 *\frac {411.687262 \ g \ PI_3}{ 1 }

1292.698 \ g\ PI_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.

  • 1292.698

The 2 in the ones place tells us to leave the 9.

1290 \ g \ PI_3

3.14 moles of phosphorous triiodide is approximately equal to <u>1290 grams of phosphorus triodide.</u>

4 0
2 years ago
23. The reaction
Sindrei [870]

Answer:

b mi disputa se eu não asetar

6 0
2 years ago
Are isotopes similar to ions, yes or no?
AysviL [449]

Answer:

Yes

Explanation:

Isotopes are atoms of the same element that have different numbers of neutrons in their nuclei. Everything else about them is the same.(If you want more explanation tell me).

5 0
1 year ago
Read 2 more answers
Iron (III) bromide reacts with sodium hydroxide to produce iron (III) hydroxide and sodium bromide. Write the balanced chemical
valkas [14]
3 NaOH + FeBr3 = 3 NaBr + Fe(OH)3

Hope this helps!!
3 0
3 years ago
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