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2 years ago

If half of the

Chemistry

1 answer:

Basile [38]2 years ago

4 0

Answer:

;-;

Explanation:

Its story is a classic example of natural selection, and of how animals can act as indicators of environmental change.

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How many square centimeters are in an area of 8.50 inch^2

Paha777 [63]

Explanation:

Given parameters:

Dimension = 8.5in²

we are to convert from in² to cm²

in² = in x in

cm² = cm x cm

1 in = 2.54cm

Using dimensional analysis;

8.5in² x $\frac{2.54cm}{1in} x \frac{2.54cm}{1in}$

= 54.84cm²

We solved this problem using dimensional analysis where we multiplied the unit with 1.

learn more:

Conversion brainly.com/question/555814

#learnwithBrainly

5 0

2 years ago

The work function for metallic potassium is 2.3 eV. Calculate the velocity in km/s for electrons ejected from a metallic potassi

mote1985 [20]

Answer:

932.44 km/s

Explanation:

Given that:

The work function of the magnesium = 2.3 eV

Energy in eV can be converted to energy in J as:

1 eV = 1.6022 × 10⁻¹⁹ J

So, work function = $2.3\times 1.6022\times 10^{-19}\ J=3.68506\times 10^{-19}\ J$

Using the equation for photoelectric effect as:

$E=\psi _0+\frac {1}{2}\times m\times v^2$

Also, $E=\frac {h\times c}{\lambda}$

Applying the equation as:

$\frac {h\times c}{\lambda}=\psi _0+\frac {1}{2}\times m\times v^2$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

m is the mass of electron having value $9.11\times 10^{-31}\ kg$

$\lambda$ is the wavelength of the light being bombarded

$\psi _0=Work\ function$

v is the velocity of electron

Given, $\lambda=260\ nm=260\times 10^{-9}\ m$

Thus, applying values as:

$\frac{6.626\times 10^{-34}\times 3\times 10^8}{260\times 10^{-9}}=3.68506\times 10^{-19}+\frac{1}{2}\times 9.11\times 10^{-31}\times v^2$

$3.68506\times \:10^{-19}+\frac{1}{2}\times \:9.11\times \:10^{-31}v^2=\frac{6.626\times \:10^{-34}\times \:3\times \:10^8}{260\times \:10^{-9}}$

$\frac{1}{2}\times 9.11\times 10^{-31}\times v^2=7.64538\times 10^{-19}-3.68506\times 10^{-19}$

$\frac{1}{2}\times 9.11\times 10^{-31}\times v^2=3.96032462\times 10^{-19}$

$v^2=0.869446\times 10^{12}$

v = 9.3244 × 10⁵ m/s

Also, 1 m = 0.001 km

5 0

2 years ago

Another chemistry question i’m not good at this at all:( has me stressed

adoni [48]

Answer:

Average atomic mass = 15.86 amu.

Explanation:

Given data:

Number of atoms of Z-16.000 amu = 205

Number of atoms of Z-14.000 amu = 15

Average atomic mass = ?

Solution:

Total number of atoms = 205 + 15 = 220

Percentage of Z-16.000 = 205/220 ×100 = 93.18%

Percentage of Z-14.000 = 15/220 ×100 = 6.82 %

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass = (93.18×16.000)+(6.82×14.000) /100

Average atomic mass = 1490.88 + 95.48 / 100

Average atomic mass = 1586.36 / 100

Average atomic mass = 15.86 amu.

5 0

3 years ago

Please help! 35 points for a valid answer!

Furkat [3]

Answer:

Oxidation half reaction is written as follows when using using reduction potential chart

example when using copper it is written as follows

CU2+ +2e- --> c(s) +0.34v

oxidasation is the loos of electron hence copper oxidation potential is as follows

cu (s) --> CU2+ +2e -0.34v

Explanation:

6 0

2 years ago

Read 2 more answers

What if you love someone a lot but are to afraid to say it?

Serjik [45]

Answer:

Zodiac signs.

Explanation:

Cringe.

4 0

2 years ago

Read 2 more answers