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3 years ago

4. Which of the following statements

Chemistry

2 answers:

Gnesinka [82]3 years ago

6 0

Answer:

The answer is B

Explanation:

hammer [34]3 years ago

3 0

Answer: Only the nervous and endocrine systems are involved in maintaining homeostasis.

Explanation: Hope this helped you

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Microwave radiation has a wavelength on the order of 1.0 cm. Calculate the frequency and the energy of a single photon of this r

denis23 [38]

Answer :

(1) The frequency of photon is, $3\times 10^{10}Hz$

(2) The energy of a single photon of this radiation is $1.988\times 10^{-23}J/photon$

(3) The energy of an Avogadro's number of photons of this radiation is, 11.97 J/mol

Explanation : Given,

Wavelength of photon = $1.0cm=0.01m$ (1 m = 100 cm)

(1) Now we have to calculate the frequency of photon.

Formula used :

$\nu=\frac{c}{\lambda}$

where,

$\nu$ = frequency of photon

$\lambda$ = wavelength of photon

c = speed of light = $3\times 10^8m/s$

Now put all the given values in the above formula, we get:

$\nu=\frac{3\times 10^8m/s}{0.01m}$

$\nu=3\times 10^{10}s^{-1}=3\times 10^{10}Hz$ $(1Hz=1s^{-1})$

The frequency of photon is, $3\times 10^{10}Hz$

(2) Now we have to calculate the energy of photon.

Formula used :

$E=h\times \nu$

where,

$\nu$ = frequency of photon

h = Planck's constant = $6.626\times 10^{-34}Js$

Now put all the given values in the above formula, we get:

$E=(6.626\times 10^{-34}Js)\times (3\times 10^{10}s^{-1})$

$E=1.988\times 10^{-23}J/photon$

The energy of a single photon of this radiation is $1.988\times 10^{-23}J/photon$

(3) Now we have to calculate the energy in J/mol.

$E=1.988\times 10^{-23}J/photon$

$E=(1.988\times 10^{-23}J/photon)\times (6.022\times 10^{23}photon/mol)$

$E=11.97J/mol$

The energy of an Avogadro's number of photons of this radiation is, 11.97 J/mol

3 0

3 years ago

Read 2 more answers

Pharmacists sometimes measure medicines in the unit of "grains," where 1 gr = 65 mg. The label on a bottle of aspirin reads "Asp

viva [34]

Answer:

325mg of Aspririn

Explanation:

First you should note the information that the problem gives you:

- The bottle of Aspirin has 5gr (grains)

- 1gr(grain) = 65mg (miligrams)

Also, the problem is asking about how many aspirin are in 5 gr (grains), so you should use a conversion factor, as follows:

-First you should put the quantity you need to convert:

$5grAspirin$

-Then you write the denominator of the conversion factor that must have the same units that you want to convert, in this case gr:

$5grAspirin*\frac{}{1grAspirin}$

-Then you write the numerator with the units that you want to obtain and the numerical equivalence between the units, in this case:

$5grAspirin*\frac{65mgAspririn}{1grAspirin}$

-Finally you multiply numerators and divide by denominators:

$5grAspirin*\frac{65mgAspririn}{1grAspirin}=325mgAspririn$

8 0

3 years ago

What geometric shape is the carbon dioxide molecule? The Lewis structure for CO2 contains two double bonds.

adelina 88 [10]

Answer: Linear

Explaination: The central atom of a carbon dioxide molecule is carbon. Carbon is tetravalent which just means it has 4 valence electrons. Because the valence shell isn’t full, the carbon atom can bond with other atoms creating a total of 4 bonds. This then allows the carbon to double bond with 2 oxygen atoms. Now, the atoms in the CO2 molecule Don’t share the electrons evenly because of atomic number or proton count. Because oxygen has an atomic number of 6, carbon has an atomic number of 4, and opposites attract (referring to the positivity of the nucleus and the negativity of the shared electrons), the oxygen atoms will have a slightly negative charge (-) and the oxygen will have a slightly positive charge (+ ). Therefore, the slightly negative oxygen atoms repel creating that linear shape.