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3 years ago

3. Which is not true about natural selection?

Chemistry

1 answer:

tatuchka [14]3 years ago

5 0

Answer:

A:There must be diversity in the population.

Explanation:

Hopefully this helps!

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Which of the following mixture types canNOT be filtered to remove solutes?

iVinArrow [24]

1. A) Colloids only

2. C) Molecules of the dispersion medium colliding with dispered phase particles

Hope this helps!

3 0

3 years ago

Using the Bohr model, determine the energy, in joules, necessary to ionize a ground-state hydrogen atom. Show your calculations.

lord [1]

Answer:

The energy required to ionize the ground-state hydrogen atom is 2.18 x 10^-18 J or 13.6 eV.

Explanation:

To find the energy required to ionize ground-state hydrogen atom first we calculate the wavelength of photon required for this operation.

It is given by Bohr's Theory as:

1/λ = Rh (1/n1² - 1/n2²)

where,

λ = wavelength of photon

n1 = initial state = 1 (ground-state of hydrogen)

n2 = final state = ∞ (since, electron goes far away from atom after ionization)

Rh = Rhydberg's Constant = 1.097 x 10^7 /m

Therefore,

1/λ = (1.097 x 10^7 /m)(1/1² - 1/∞²)

λ = 9.115 x 10^-8 m = 91.15 nm

Now, for energy (E) we know that:

E = hc/λ

where,

h = Plank's Constant = 6.625 x 10^-34 J.s

c = speed of light = 3 x 10^8 m/s

Therefore,

E = (6.625 x 10^-34 J.s)(3 x 10^8 m/s)/(9.115 x 10^-8 m)

E = 2.18 x 10^-18 J

E = (2.18 x 10^-18 J)(1 eV/1.6 x 10^-19 J)

E = 13.6 eV

5 0

3 years ago

Which atom or ion is the largest? A. K B. K+ C. Ca D. Ca2+ E. Li

pishuonlain [190]

Answer:

A. K

Step-by-step explanation:

Remember the trends in the Periodic Table:

Atomic radii decrease from left to right across a Period.
Atomic radii increase from top to bottom in a Group.
Ionic radii of metal cations are smaller than those of their atoms.

Thus, the largest atoms are in the lower left corner of the Periodic Table.

The diagram below shows that K is closest to the lower left, so it is the largest atom. It is also larger than any of the cations.

5 0

3 years ago

I will go to the app and give you brainly Est if u answer correctly ASAPPPPP

zhuklara [117]

Answer:

Explanation:

I think it is C

4 0

2 years ago

The addictive power of nicotine is enhanced by which of the following chemicals?

ArbitrLikvidat [17]

The correct answer is A. Ammonia.

5 0

3 years ago