How many electrons does the copper atom lose in the process: Cu → Cu3+ + ? electrons

Photosynthesis uses 660-nm light to convert co2 and h2o into glucose and o2. calculate the frequency of this light.

Allushta [10]

The unit expressed in 660 nm of light represents the wavelength of light. If you want to determine the frequency, you use the speed of light to relate the two. The formula is:

c = λν
where
λ is the wavelength
ν is the frequency
c is the speed of light = 3×10⁸ m

Apply SI units:
(3×10⁸ m) = (660×10⁻⁹ m)(ν)
Solving for ν,
<em>ν = 4.55×10¹⁴ s⁻¹</em>

4 0

3 years ago

What mass of nitrogen is needed to fill an 855 L tank at STP?

scoundrel [369]

Answer:

It takes 1,068.76 grams of nitrogen to fill an 855 L tank at STP.

Explanation:

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C or 273.15 °K are used and are reference values for gases.

On the other side, the pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:

P*V = n*R*T

where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas.

So, in this case:

P= 1 atm
V= 855 L
n= ?
R= 0.082 $\frac{atm*L}{mol*K}$
T= 273.15 K

Replacing:

1 atm* 855 L= n* 0.082 $\frac{atm*L}{mol*K}$ * 273.15 K

Solving:

$n=\frac{1 atm* 855 L}{0.082\frac{atm*L}{mol*K} *273.15 K }$

n= 38.17 moles

Being the molar mass of nitrogen N2 equal to 28 g / mol, you can apply the following rule of three: if there are 28 grams in 1 mole, how much mass is there in 38.17 moles?

$mass=\frac{38.17 moles*28 grams}{1 mole}$

mass= 1,068.76 grams

<u><em> It takes 1,068.76 grams of nitrogen to fill an 855 L tank at STP.</em></u>

3 0

3 years ago

Describe the properties of alkali metals. Based on their electronic arrangement, explain whether they exist alone in nature.

bearhunter [10]

Answer:

- They are highly reactive metals

- They have low electro negativity

- They have low ionization energy

- They don't exist alone in nature

- They have low densities

Explanation:

Alkali metals are the elements in group 1 of the periodic table. They include Sodium, Lithium, Potassium e.t.c.

Due to the fact they have one atom in their outermost shell, they are very unstable because they easily react with other elements and are therefore don't exist alone in nature but combined with other elements for this same reason.

Since alkali metals don't easily attract other elements due to it's lone pair in the outer most shell, it can be said to have low electro negativity.

Also, they don't need energy to discharge their electrons since they are highly reactive due to their lone pair in the outermost shell and so we say they have low ionization energy.

Due to this reason, they also have low densities.

7 0

2 years ago

A total solar eclipse occurs because the moon can totally block the sun. If the moon was smaller or farther from earth, a total

Setler79 [48]

Answer:

both

Explanation:

id say that it could occur but also not as much. the moon would be smaller and further from the earth to where we would barely be able to see it. if the full moon is barely visible then im sure the total solar eclipse wouldn't be as noticeable as it is now. but thats just my opinion

6 0

2 years ago

How much (Q) heat is needed to melt 35 g of iodine? Hf = 61.7 J/g.

aev [14]

Taking into account the definition of calorimetry and latent heat, a heat of 2159.5 J is needed to melt 35 g of iodine.

<h3>Calorimetry</h3>

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

<h3>Latent heat</h3>

Latent heat is defined as the energy required by a quantity of substance to change state.

When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.

The heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to

Q = m×L

where L is called the latent heat of the substance and depends on the type of phase change.

<h3>Heat needed to melt iodine</h3>

In this case, you know: