What is a base used in toothpaste?

A laser produces red light of wavelength 632.8 nm. Calculate the energy,

Ira Lisetskai [31]

Answer:

189.2 KJ

Explanation:

Data Given

wavelength of the light = 632.8 nm

Convert nm to m

1 nm = 1 x 10⁻⁹

632.8 nm = 632.8 x 1 x 10⁻⁹ = 6.328 x 10⁻⁷m

Energy of 1 mole of photon = ?

Solution

Formula used

E = hc/λ

where

E = energy of photon

h = Planck's Constant

Planck's Constant = 6.626 x 10⁻³⁴ Js

c = speed of light

speed of light = 3 × 10⁸ ms⁻¹

λ = wavelength of light

Put values in above equation

E = hc/λ

E = 6.626 x 10⁻³⁴ Js ( 3 × 10⁸ ms⁻¹ / 6.328 x 10⁻⁷m)

E = 6.626 x 10⁻³⁴ Js (4.741 x 10¹⁴s⁻¹)

E = 3.141 x 10⁻¹⁹J

3.141 x 10⁻¹⁹J is energy for one photon

Now we have to find energy of 1 mole of photon

As we know that

1 mole consists of 6.022 x10²³ numbers of photons

So,

Energy for one mole photons = 3.141 x 10⁻¹⁹J x 6.022 x10²³

Energy for one mole photons = 1.89 x 10⁵ J

Now convert J to KJ

1000 J = 1 KJ

1.89 x 10⁵ J = 1.89 x 10⁵ /1000 = 189.2 KJ

So,

energy of one mole of photons = 189.2 KJ

3 0

2 years ago

The image represents a(n)

Archy [21]

Answer:

B) atom of Xenon

Explanation:

Xenon is already stable alone, because it has a complete octet, or 8 electrons. This graph is not an ion because it shows xenon is its default state, consisting of 8 electrons.

It is not a molecule because a molecule is a group of atoms, or a compound, what is shown is a singular atom.

7 0

2 years ago

Read 2 more answers

The matter in this series of images is going through a change. Draw a conclusion about the type of change shown. Is it a physica

34kurt

Answer:

This is a chemical change because it has been lit on fire. When it is lit on fire, the fire has been made, heat has been made, and gasses produced from the fire have also been made. Because this introduces new matter to the pictures, it is a chemical reaction.

Explanation:

8 0

2 years ago

Someone please help me with number 5. no idea what it is.

KATRIN_1 [288]

Answer is Sodium Hydroxide.

5 0

2 years ago

The following list contains some common radicals. Using the charges on these ions and the idea of valence, predict the formulas

lesantik [10]

Answer : The formula for the compound sodium carbonate is $Na_2CO_3$

The formula for the compound potassium permanganate is $KMnO_4$

Explanation :

For formation of a neutral ionic compound, the charges on cation and anion must be balanced.

The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non-metals.

(a) Sodium carbonate

In the compound, the sodium metal forms an ionic compound with polyatomic anion (carbonate) $CO_3^{2-}$ .

Here, sodium is having an oxidation state of +1 called as $Na^{1+}$ cation and carbonate $CO_3^{2-}$ is an anion with oxidation state of -2. The charges are not balanced. So, the charges are balanced by the cris-cross method. Thus, the compound formed will be, $Na_2CO_3$

Hence, the formula for the compound sodium carbonate is $Na_2CO_3$

(b) Potassium permanganate

In the compound, the potassium metal forms an ionic compound with polyatomic anion (permanganate) $MnO_4^{1-}$ .

Here, potassium is having an oxidation state of +1 called as $K^{1+}$ cation and permanganate $MnO_4^{1-}$ is an anion with oxidation state of -1. The charges are balanced. Thus, the compound formed will be, $KMnO_4$

Hence, the formula for the compound potassium permanganate is $KMnO_4$

3 0

2 years ago