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Elza [17]

Answer:Sound waves are longitudinal waves that travel through a medium like air or water. When we think about sound, we often think about how loud it is (amplitude, or intensity) and its pitch (frequency).

Explanation:

6 0

3 years ago

Two moles of magnesium (Mg) and five moles of oxygen (O2) are placed in a

I am Lyosha [343]

First off, the chemical equation needs to be balanced. Since there are 2 oxygen atoms in the reactants, we must produce 2 moles of MgO, which means we need 2 moles of Mg, giving:
2Mg + O2 --> 2MgO
Therefore for a stoichiometric reaction where no reactant is left over, the number of moles of magnesium must be double that of oxygen. However, as seen, the molar ratio of magnesium to oxygen is 2:5, meaning oxygen is in large excess, and Magnesium is the limiting reactant. Therefore the answer is A.

8 0

3 years ago

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Question 3 (2 points)

Mademuasel [1]

Answer:sksk

Explanation:sksk

4 0

3 years ago

Ultraviolet radiation and radiation of shorter wavelengths can damage biological molecules because they carry enough energy to b

DIA [1.3K]

<h3>Answer:</h3>

Longest wavelength = 343.7 nm

<h3>Solution and Explanation:</h3>

In this question we need to first use the concept of energy of a photon.

Energy of a photon, E, is given by the formula, E = hf, where h is the plank's constant, f is the frequency.

But since, f is given by dividing speed, c, by wavelength, λ, then;

E = hc/λ

We are given 348 kJ/mol required to break carbon-carbon bonds.

We know that; 1 mole of bonds = 6.022 × 10^23 bonds.

We are required to find the longest wavelength with enough energy to break the C-C bonds.

This can be worked out in simple steps:

Step 1: Energy required to break one bond (kJ/bond)

1 mole of bonds = 6.022 × 10^23 bonds.

Therefore;

348 kJ = 6.022 × 10^23 bonds.

Thus;

1 bond = 348 kJ ÷ 6.022 × 10^23 bonds.

= 5.778 x 10^-22 kJ

But; 1000 joules = 1 kJ

Hence; energy per bond = 5.778 x 10^-19 Joules

Step 2: Energy per photon

Breaking one bond requires energy equivalent to energy of a photon.

Therefore;

1 photon = 5.778 x 10^-19 Joules

= 5.778 x 10^-19 J/photon

Step 3: Calculating the wavelength

From the equation of energy of a photon;

E = hc/λ

h is the plank's constant = 6.626 × 10^-34 J/s

c is the speed of light in vacuum = 2.9998 × 10^8 m/s

E is the energy of a photon = 5.778 x 10^-19 Joules

Therefore, making λ (wavelength) the subject;

$wavelength = \frac{hc}{E}$

$= \frac{(6.626 . 10^{-34})(92.9998.10^8) }{(5.778 .10^{-19} )}$

$= 3.437. 10^{-7} m$

= 3.437 x 10^-7 m

But; 1 nm = 10^-9 m

Thus;

wavelength = 343.7 nm

Therefore, the longest wavelength of the radiation will be 343.7 nm

5 0

3 years ago

How do chemical weathering and the formation of biochemical sediment remove carbon from the atmosphere and store it in the geosp

Sav [38]

The chemical weathering process of carbonation removes carbon from the atmosphere. In this process, carbon dioxide in the atmosphere mixes with rainfall to form carbonic acid. This acid then reacts with calcium carbonate or limestone to form calcium bicarbonate. This reaction removes carbon from the atmosphere. Organisms such as corals can remove dissolved carbon from oceans to form their hard rocky structures. Carbon dioxide from the atmosphere is dissolved in ocean water. Overtime they become limestone rock.

6 0

4 years ago