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Which of the following are excited in ultraviolet photoelectron spectroscopy?

zavuch27 [327]

Answer:

D. Valance Electrons

Explanation:

6 0

3 years ago

Why do atoms move at different speeds depending on whether they are in liquids or solids.

bekas [8.4K]

In a solid the atoms are tightly packed together and vibrate in place, in a liquid the atoms are loosely packed together and can move past each other,

extra: and in a gas the atoms are far apart and move freely and

6 0

3 years ago

How many grams are in 1.76 x 10^23 atoms of iodine

Mariana [72]

Answer:

$\boxed {\boxed {\sf About \ 37.1 \ grams \ of \ iodine }}$

Explanation:

To convert from atoms to grams, you must first convert atoms to moles, then moles to grams.

1. Convert Atoms to Moles

To convert atoms to grams, Avogadro's number must be used.

$6.022*10^{23}$

This number tells us the number of particles (atoms, molecules, ions, etc.) in 1 mole. In this case, the particles are atoms of iodine.

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

Multiply the given number of atoms by Avogadro's number.

$1.76*10^{23} \ atoms \ I*\frac{6.022*10^{23} \ atoms \ I }{1 \ mol \ I}$

Flip the fraction so the atoms of iodine will cancel out.

$1.76*10^{23} \ atoms \ I*\frac{ 1 \ mol \ I}{6.022*10^{23} \ atoms \ I}$

$1.76*10^{23}* \frac{1 \ mol \ I}{6.022*10^{23} }$

Multiply so the problem condenses into 1 fraction.

$\frac{1.76*10^{23} \ mol \ I}{6.022*10^{23} }$

$0.2922617071 \ mol \ I$

2. Convert Moles to Grams

Now we must use the molar mass of iodine, which is found on the Periodic Table.

Iodine Molar Mass: 126.9045 g/mol

Use this mass as a fraction.

$\frac{ 126.9045 \ g\ I }{ 1 \ mol \ I}$

Multiply this fraction by the number of moles found above.

$0.2922617071 \ mol \ I*\frac{ 126.9045 \ g\ I }{ 1 \ mol \ I}$

Multiply. The moles of iodine will cancel.

$0.2922617071 *\frac{ 126.9045 \ g\ I }{ 1 }$

The 1 as a denominator is insignificant.

$0.2922617071 *{ 126.9045 \ g\ I }$

$37.08932581 \ g \ I$

3. Round

The original measurement of 1.76*10^23 has 3 significant figures (1, 7, and 6). Therefore we must round our answer to 3 sig figs. For this answer, that is the tenths place.

$37.08932581 \ g \ I$

The 8 in the hundredth place tells us to round the 0 up to a 1.

$\approx 37.1\ g \ I$

There is about 37.1 grams of iodine in 1.76*10^23 atoms.

5 0

3 years ago

True or False : An object can be in motion and not in motion at the same time depending on which frame of reference you are comp

marshall27 [118]

Answer:

True

Explanation:

Yes I agree object can be in motion and in not motion at the same time for example there are two men travelling on the bus one person is A another person is B. the person be B rest so by seeing person be the person A also sits but the person see who saw the person be B move along with person C so the the person be B is in rest for person Abut is motion for a person C.

3 0

3 years ago

1. How many mg of lithium phosphide are in 18.0 mL of a 1.25 M solution?

Temka [501]

Answer:

1160mg

Explanation:

Molarity = number of moles ÷ volume

According to the information in the question, molarity = 1.25 M, volume = 18.0 mL = 18/1000 = 0.018L

M = n/V

n = M × V

n = 1.25 × 0.018

n = 0.0225moles.

Using mole = mass/molar mass, to find the mass of lithium phosphide (Li3P)

Molar mass of Li3P = 6.9(3) + 31 = 51.7g/mol

mole = mass/molar mass

0.0225 = mass/51.7

mass = 1.16grams.

In milligrams (mg), mass of Li3P = 1.16 × 1000 = 1160mg

6 0

3 years ago