What modifications were made to the original Ray Cathode experiment?

A party balloon contains 5.50 x 10 ^22 atoms of helium gas. What is the mass, in grams of the

eduard

Answer:

$\boxed {\boxed {\sf A. \ 0.365 \ g\ He}}$

Explanation:

1. Convert Atoms to Moles

We must use Avogadro's Number: 6.022*10²³. This is the number of particles (atoms, molecules, ions, etc.) in 1 mole of a substance. In this case, the particles are atoms of helium. We can create a ratio.

$\frac {6.022*10^{23} \ atoms \ He}{1 \ mol \ He}$

Multiply by the given number of helium atoms.

$5.50 *10^{22} \ atoms \ He *\frac {6.022*10^{23} \ atoms \ He}{1 \ mol \ He}$

Flip the fraction so the atoms of helium cancel.

$5.50 *10^{22} \ atoms \ He *\frac {1 \ mol \ He}{6.022*10^{23} \ atoms \ He}$

$5.50 *10^{22} *\frac {1 \ mol \ He}{6.022*10^{23} }$

$\frac {5.50 *10^{22} \ mol \ He}{6.022*10^{23} }= 0.09133178346 \ mol \ He$

2. Convert Moles to Grams

We must use the molar mass, which is found on the Periodic Table.

Helium (He): 4.00 g/mol

Use this as a ratio.

$\frac { 4.00 \ g \ He }{ 1 \ mol \ He}$

Multiply by the number of moles we calculated. The moles will then cancel.

$0.09133178346 \ mol \ He *\frac { 4.00 \ g \ He }{ 1 \ mol \ He}$

$0.09133178346*\frac { 4.00 \ g \ He }{ 1 }$

$0.3653271338 \ g\ He$

3. Round

The original measurement has 3 significant figures (5, 5, and 0). Our answer must have the same. For the number we calculated, it is thousandth place. The 3 in the ten thousandth place tells us to leave the 5.

$0.365 \ g\ He$

The mass is 0.365 grams of helium so choice A is correct.

7 0

3 years ago

Baseball traveling (+30 m/s) and is hit by a bat. it leaves the bat traveling (-40 m/s) what is the change in the velocity? reme

castortr0y [4]

The answer it 70 I think try it

3 0

3 years ago

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Give two reasons why quarrying is bad for the enviroment

Elza [17]

Air & noise pollution
Quarry waste
Damage to biodiversity

6 0

3 years ago

If you were asked to convert 25 cg to the unit hg, which of the following would be the first fraction used in the conversion? on

zhannawk [14.2K]

We are asked to convert 25 cg to units of hg.

1 cg = 1 centigram = 10⁻² g
1 hg = 1 hectogram = 10² g

The options given are:

a) 1 hg/ 10² g
b) 10² cg/ 1 hg
c) 10² hg/ 1 cg
d) 10⁻² g/ 1 cg

To convert 25 cg to 1 hg, we could convert the 25 cg to grams first, then grams to hg.

25 cg · 10⁻² g/ 1cg = 0.25 g

Here we have converted our number from cg to grams. We can use another conversion of grams to hg to complete the conversion.

0.25 g · 1 hg/ 10² g = 0.0025 hg

Therefore, the first conversion we used was d) 10⁻² g/ 1 cg.

4 0

3 years ago

Which element would you expect to be more reactive: phosphorus (P) or fluorine (F)

Studentka2010 [4]

Answer:

Fluorine

Explanation:

Fluorine is the most electronegative element because it has 5 electrons in it's 2P shell.

4 0

3 years ago

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