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3 years ago

What is name of first man made element?

1 answer:

4 0

The first man-made element or artificial element which is produced because it is not found naturally in nature is Technicium, in 1937. Technicium has an atomic number of 43 and atomic mass of 98 g/mol.

You might be interested in

How many neutrons are in an atom with atomic number of 53 and mass number of 127?

asambeis [7]

Atomic number = 127 – 53=74 neutrons

8 0

3 years ago

Which of the following examples illustrates a number that is correctly rounded to three significant figures? Which of the follow

Alex

Answer:

20.0332 grams to 20.0 grams

Explanation:

6 0

3 years ago

Calculate the concentration of clo2− at equilibrium if the initial concentration of hclo2 is 2. 25×10^−2 m.

jek_recluse [69]

The concentration of ClO₂⁻ at equilibrium if the initial concentration of HClO₂ is 0.0654.

<h3>What is concentration?</h3>

The concentration of any substance is the quantity of that substance in per square of the space or container.

The reaction is

HClO₂ + H₂O <=> H₃O⁺ + ClO₂⁻

The pH is 0.454 M

Ka = [H₃O⁺][ClO₂⁻ ] / [HClO₂]

2. 25 × 10⁻² m = [x][x] / 0.454-x]

2 + 0.011 - 0.004994 = 0

solve the quadratic equation

x = 0.0654 = [H3O+] = [ClO2-]

pH = -log (H3O+)

pH = -log(0.0654)

pH = 1.2

equilibrium concentrations of

[HClO2] = 0.454 -x = 0.454 -0.0654 = 0.3886 M

[ClO2- ] = x = 0.0654

Thus, the equilibrium concentrations is 0.0654.

To learn more about concentration, refer to the link:

brainly.com/question/16645766

#SPJ4

6 0

1 year ago

Make the following conversions. Show your calculations.

Natalija [7]

Answer:

1. 500 cm = 5 m

2. 1000 g = 1 kg

3. 455 L = 45, 500 cL

4. 0.865 m = 0.00865 m or 8.65 * 10^-3 n

5. 33.5 cm = 335 mm

6. 0.0198 m = 19800 micrometers

7. 57.65 cg = 5.765 * 10^8 nanograms

8. 1000 L = 1 kl

9. 99 degrees F = 37.222 degrees C

Explanation:

1. One meter = 100 centimeters

500 centimeters/ 100 centimeters = 5 meters

2. One kilogram = 1000 grams.

1000 grams/1000 grams = 1 kilogram

3. One Liter = 100 centiliters

455 liters * 100 centiliters = 45, 500 centiliters

4. One meter = 100 centimeters

0.865 centimeters/100 centimeters = 0.00865 meters

5. One centimeter = 10 millimeters

33.5 centimeters * 10 millimeters = 335 millimeters

6. One meter = 1.0 * 10^6 micrometers

0.0198 meters * 1 * 10^6 micrometers = 19800 micrometers.

7. One centigram = 1.0 * 10^7 nanograms

57.65 centigrams * 1 * 10^7 nanograms = 5.765 * 10^8 nanograms.

8. One kiloliter = 1000 L

1000 L/ 1000 L = 1 kiloliter

9. The formula for finding Celsius is 5/9(f - 32)

So 5/9(99 - 32) = x

5/9(67) = x

x = 335/9 or 37.222 degrees Celsius.

5 0

3 years ago

What coefficient should be used to make the following equation balanced? N2+O2--> _NO

IgorLugansk [536]

<h2> ║∧║······→Hello.←······║∧║</h2>

Your answer should be:

N2 + O2 → 2NO

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7 0

3 years ago