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lawyer [7]
3 years ago
11

Please help me with my science thank you!

Chemistry
1 answer:
Tatiana [17]3 years ago
4 0
I cant see it maybe post it again?
You might be interested in
What minimum frequency of light is required to ionize boron?
Nadusha1986 [10]

Answer:

frequency  = 8.22 x 10¹⁴ s⁻¹

Explanation:

An electron's positional potential energy while in a given principle quantum energy level is given by Eₙ = - A/n² and A = constant = 2.18 x 10⁻¹⁸j. So to remove an electron from the valence level of Boron (₅B), energy need be added to promote the electron from n = 2 to n = ∞. That is, ΔE(ionization) = E(n=∞) - E(n=2) = (-A/(∞)²) - (-A/(2)²) = [2.18 x 10⁻¹⁸j/4] joules = 5.45 x 10⁻¹⁹ joules.

The frequency (f) of the wave ionization energy can then be determined from the expression ΔE(izn) = h·f; h = Planck's Constant = 6.63 x 10⁻³⁴j·s. That is:

ΔE(izn) = h·f => f = ΔE(izn)/h = 5.45 x 10⁻¹⁹ j/6.63 x 10⁻³⁴ j·s = 8.22 x 10¹⁴ s⁻¹

3 0
3 years ago
Which is a mixture?
Rama09 [41]
Potassium and chlorine
5 0
4 years ago
Read 2 more answers
compound of aspartame is a dipeptide that is often used as a sugar substitute which functional groups are present
Scrat [10]

Answer:

Carboxyl, primary amine, amide, ester, and phenyl.

Explanation:

The functional groups present in the compound of aspartame are carboxyl, primary amine, amide, ester, and phenyl. Aspartame is an artificial non-saccharide sweetener which is 200 times sweeter than sucrose. This aspartame is commonly used as a sugar substitute in many foods and beverages. It has the trade names such as NutraSweet, Equal, and Canderel.

5 0
3 years ago
A beach ball has a mass of 5 g and a volume of 20 cm3. What is the object's density?
ivann1987 [24]
Mass = 5 g

volume = 20 cm³

density = mass / volume

therefore:

D = m / V

D = 5 / 20

D = 0.25 g/cm³
3 0
4 years ago
Match the statements with the atmospheric layer they describe.
vekshin1

The correct matches are:

1. Exosphere - Temperatures reach as high as 2000 C yet it feels very cold

This is the top layer of the atmosphere. The atoms are so dispersed that despite it having very high temperature it doesn't feel like it at all.

2. Thermosphere - Particles that have enough energy can escape into space

The thermosphere is the fourth highest layer of the atmosphere. The atoms in this layer are relatively distant from one another, so the particles that have enough energy manage to escape easily into the exosphere and then the space.

3. Mesosphere - It is the coldest region of the atmosphere

The mesosphere is the third highest layer. In this layer the temperatures constantly drop, and they go down to -85 degrees, making it the coldest layer by far.

4. Stratosphere - Ninety percent ozone is in this layer

The startosphere has a separte zone in it which is dominated by only one gas, the ozone. It is called the ozone layer, the one that protects the Earth from too intense UV radiation, and in fact over 90% of this gas is locate here.

5. Troposphere - It is warm due to the heat from Earth's surface

The troposphere is the densest and lowest of the layers. It is the one that also has Greenhouse gases which manage to trap the heat that is radiated from the surface of the Earth, thus keeping this layer relatively warm.

6 0
4 years ago
Read 2 more answers
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