Which source of energy causes most of the water evaporation on Earth’s surface?

How many photons are produced in a laser pulse of 0.364 J at 477 nm?

Luda [366]

Answer:

1.00 × 10¹⁸

Explanation:

1. Calculate the energy of one photon

The formula for the energy of a photon is

E = hc/λ

h = 6.626 × 10⁻³⁴ J·s; c = 2.998 × 10⁸ m·s⁻¹

λ = 477 nm = 477 × 10⁻⁹ m Insert the values

E = (6.626 × 10⁻³⁴ × 2.998× 10⁸)/(477 × 10⁻⁹)

E = 4.165× 10⁻¹⁹ J

2. Calculate the number of photons

Divide the total energy by the energy of one photon.

No. of photons = 0.418 × 1/4.165 × 10⁻¹⁹

No. of photons = 1.00 × 10¹⁸

7 0

3 years ago

A Metal pan will heat up quickly when placed over a gas or electric burner. The Metal pan is a good what...

Alik [6]

Answer:

heating up, lol

Explanation:

8 0

2 years ago

If the atomic number of an element is 9 and the mass number is 19, how many neutrons does the atom have? 10 9 19 28 1 points

IRINA_888 [86]

Remember....

mass number= atomic number + number of neutrons

If the mass number is 19 and the atomic number is 9, then the number of neutrons is 19-9 which is 10.

6 0

3 years ago

Predict the products of each of the following reactions and then balance the chemical equations.

Nookie1986 [14]

Answer: The chemical equations are given below.

Explanation:

For a: Fe is heated in an atmosphere of steam.

The chemical equation follows:

$3Fe(s)+4H_2O(g)\rightarrow Fe_3O_4(s)+4H_2(g)$

By Stoichiometry of the reaction:

3 moles of iron reacts with 4 moles of steam to produce 1 mole of iron (II,III) oxide and 4 moles of hydrogen.

For b: NaOH is added to a solution of $Fe(NO_3)_3$

The chemical equation follows:

$Fe(NO_3)_3+3NaOH\rightarrow Fe(OH)_2+3NaNO_3$

By Stoichiometry of the reaction:

1 mole of iron nitrate reacts with 3 moles of sodium hydroxide to produce 1 mole of iron hydroxide and 3 moles of sodium nitrate.

For c: $FeSO_4$ is added to an acidic solution of $KMnO_4$

The chemical equation follows:

$10FeSO_4+2KMnO_4+8H_2SO_4\rightarrow 5Fe_2(SO_4)_3+K_2SO_4+2MnO_4+8H_2O$

By Stoichiometry of the reaction:

10 moles of iron(II) sulfate reacts with 2 moles of potassium permangante and 8 moles of sulfuric acid to produce 5 moles of iron(III) sulfate, 1 mole of potassium sulfate, 2 moles of manganese oxide and 8 moles of water.

For d: Fe is added to a dilute solution of $H_2SO_4$

The chemical equation follows:

$Fe+H_2SO_4\rightarrow FeSO_4+H_2$

By Stoichiometry of the reaction:

1 mole of iron reacts with 1 mole of sulfuric acid to produce 1 mole of iron sulfate and 1 mole of hydrogen gas.

For e: A solution of $Fe(NO_3)_2$ and $HNO_3$ is allowed to stand in air.

The chemical equation follows:

$3Fe(NO_3)_2+4HNO_3\rightarrow 3Fe(NO_3)_3+NO+H_2O$

By Stoichiometry of the reaction:

3 moles of iron(II) nitrate reacts with 4 moles of nitric acid to produce 3 moles of iron(III) nitrate, 1 mole of nitric oxide and 1 mole of water.

For f: $FeCO_3$ is added to a solution of $HClO_4$

The chemical equation follows:

$FeCO_3+2HClO_4\rightarrow Fe(ClO_4)_2+CO_2+H_2O$

By Stoichiometry of the reaction:

1 mole of iron(II) carbonate reacts with 2 moles of perchloric acid to produce 1 moles of iron(II) perchlorate, 1 mole of carbon dioxide and 1 mole of water.