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3 years ago

Look at the bottom of the periodic table. There are two rows of elements separated from the others. Where do these

Chemistry

1 answer:

mina [271]3 years ago

4 0

Answer:

The first row of elements fits in period 6, after the element lanthanum (La). The second row of elements fits in period 7, after the element actinium (Ac). 

I hope this helps!

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Light strikes a beautiful white perch under water. This light is reflected back to your eyes allowing you to see the fish. As th

Ivahew [28]

The answer is: Light strikes a beautiful white perch under water. This light is reflected back to your eyes allowing you to see the fish. As the light left the water it changes speed causing the light to bend away from the normal.
Hope this helps!
(i got this from https://quizlet.com/5474123/chapter-13-light-flash-cards/ if you need more help)

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2 years ago

Consider the four free body diagrams. Free-body diagrams are diagrams used to show the relative magnitude and direction of all f

9966 [12]

If you look closely at each of the four diagrams you would be able to conclude that

D)
Yes. In B and D. In both cases, there is a net force.
In B, there is a net force to the left; in D there is a net force upward.

In A and C, the forces are in equilibrium both in the horizontal and vertical direction.

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3 years ago

Read 2 more answers

What happens in the process of beta decay?

Andrej [43]

Answer:

A neutron transforms into a proton and an electron.

Explanation:

i took the test got an 100%

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3 years ago

You determine that it takes 26.0 mL of base to neutralize a sample of your unknown acid solution. The pH of the solution was 7.8

Lubov Fominskaja [6]

Complete Question

You determine that it takes 26.0 mL of base to neutralize a sample of your unknown acid solution. The pH of the solution was 7.82 when exactly 13 mL of base had been added, you notice that the concentration of the unknown acid was 0.1 M. What is the pKa of your unknown acid?

Answer:

The pK_a value is $pK_a =7.82$

Explanation:

From the question we are told

The volume of base is $V_B = 26.mL = 0.0260L$

The pH of solution is $pH = 7.82$

The concentration of the acid is $C_A = 0.1M$

From the pH we can see that the titration is between a strong base and a weak acid

Let assume that the the volume of acid is $V_A = 18mL= 0.018L$

Generally the concentration of base

$C_B = \frac{C_AV_A}{C_B}$

Substituting value

$C_B = \frac{0.1 * 0.01800}{0.0260}$

$C_B= 0.0692M$

When 13mL of the base is added a buffer is formed

The chemical equation of the reaction is

$HA_{(aq)} + OH^-_{(aq)} --------> A^{+}_{(aq)} + H_2 O_{(l)}$

Now before the reaction the number of mole of base is

$No \ of \ moles[N_B] = C_B * V_B$

Substituting value

$N_B = 0.01300 * 0.0692$

$= 0.0009 \ moles$

Now before the reaction the number of mole of acid is

$No \ of \ moles = C_B * V_B$

Substituting value

$N_A = 0.01800 *0.1$

$= 0.001800 \ moles$

Now after the reaction the number of moles of base is zero i.e has been used up

this mathematically represented as

$N_B ' = N_B - N_B = 0$

The number of moles of acid is

$N_A ' = N_A - N_B$

$= 0.0009\ moles$

The pH of this reaction can be mathematically represented as

$pH = pK_a + log \frac{[base]}{[acid]}$

Substituting values

$7.82 = pK_a +log \frac{0.0009}{0.0009}$

$pK_a =7.82$

8 0

2 years ago

Why was alchemy so confusing?

galina1969 [7]

Search Results
Featured snippet from the web
Alchemy is extremely complicated. It is based on the practical skills of early metal workers and craftsmen, on Greek philosophy, and on Eastern mystic cults that sprang up in the first centuries after Christ and influenced so much of magic and occult thought.

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2 years ago