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3 years ago

Make the selection that best completes the sentence.

Chemistry

2 answers:

mylen [45]3 years ago

5 0

The answer would be C. in an ellipse

Hope this answer helps!

Vlad [161]3 years ago

5 0

The answer is C, in an ellipse.

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The first ionization energy of na(g) is 0.50 mj/mole. can a photon with a wavelength of 500 nm ionize a sodium atom? explain.

Sonbull [250]

<h3>Answer:</h3>

No, a photon with a wavelength of 500 nm can't ionize a sodium atom.

<h3>Explanation:</h3>

Step 1: Find out Energy of given wavelength:

The relation between wavelength and frequency is as follow,

υ = c / λ

where

υ = frequency = ?

c = velocity of light = 3.0 × 10⁸ ms⁻¹

λ = wavenumber = 500 nm = 500 × 10⁻⁹ m

Putting the given values,

υ = 3.0 × 10⁸ ms⁻¹ / 500 × 10⁻⁹ m

υ = 6.0 × 10¹⁴ s⁻¹

Also we know that,

E = h υ

Where;

E = Energy

h = Plank's Constant = 6.6262 × 10⁻³⁴ Js

Putting value of frequency,

E = 6.6262 × 10⁻³⁴ Js × 6.0 × 10¹⁴ s⁻¹

E = 3.97 × 10⁻¹⁹ J

Step 2: Compare given energy and calculated energy:

As we know,

0.5 mJ = 500000 J

Also,

500000 J > 3.97 × 10⁻¹⁹ J

<h3>Conclusion:</h3>

The energy of calculated wavelength of photon is less than 0.5 mJ hence, it is unable to ionize sodium atom.

4 0

3 years ago

Read 2 more answers

Hydrochloric acid reacts with sodium hydroxide to produce sodium chloride and water. If 20.6 g of sodium hydroxide reacts with a

astraxan [27]

Answer:

30.1 g NaCl

Explanation:

Your first conversion is converting grams NaOH to moles of NaOH using its molar mass (39.997 g/mol). Then, use the mole ratio of 1 mol NaCl for every 1 mol NaOH to get to moles of NaCl. Then finally multiply by the molar mass of NaCl (58.44 g/mol) to get grams of NaCl.

20.6 g NaOH • (1 mol NaOH / 39.997 g NaOH) • (1 mol NaCl / 1 mol NaOH) • (58.44 g NaCl / 1 mol NaCl) = 30.1 g NaCl

4 0

3 years ago

In a chemical reaction, sulfur (S8) combines with copper to give a pure compound. If you start with 1.000 g of sulfur (S8) and o

Airida [17]

<u>Answer:</u> The empirical formula for the given compound is $Cu_2S$

<u>Explanation:</u>

We are given:

Mass of pure compound containing copper and sulfur = 4.963 g

Mass of S = 1.000 g

Mass of Cu = (4.963 - 1.000) g = 3.963 g

To formulate the empirical formula, we need to follow some steps:

<u>Step 1:</u> Converting the given masses into moles.

Moles of Copper = $\frac{\text{Given mass of Copper}}{\text{Molar mass of Copper}}=\frac{3.963g}{63.55g/mole}=0.0624moles$

Moles of Sulfur = $\frac{\text{Given mass of Sulfur}}{\text{Molar mass of Sulfur}}=\frac{1.000g}{32g/mole}=0.0312moles$

<u>Step 2:</u> Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.0312 moles.

For Copper = $\frac{0.0624}{0.0312}=2$

For Sulfur = $\frac{0.0312}{0.0312}=1$

<u>Step 3:</u> Taking the mole ratio as their subscripts.

The ratio of Cu : S = 2 : 1

Hence, the empirical formula for the given compound is $Cu_2S$

8 0

3 years ago

1.15 g of a metallic element reacts with 300 cm3 of oxygen at 298 K and 1 atm pressure, to form. an oxide which contains O2– ion

Deffense [45]

D sodium
hope it helps

5 0

3 years ago

Explain how you would find the mass percent<br> of each element in water.

nydimaria [60]

Answer:

finding the mass percentage oven element in a compound might sound complicated, but the calculation is simple. For example, to determine the mass percentage of hydrogen in water H2O, divide the major mass of hydrogen by the total molar mass of water and then multiply the result by 100

3 0

3 years ago