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earnstyle [38]
2 years ago
5

Looking across period 4 of the periodic table, potassium (atomic number 19) is followed by calcium (atomic number 20), which is

followed by scandium (atomic number 21). Which element should have the largest atomic radius? A) potassium B)calcium C)scandium D)All three have the same atomic radius.
Chemistry
2 answers:
Mumz [18]2 years ago
8 0
While staying in the same period, if we move from left to right across the period, the atomic radius decreases. The reason is, in a period the number of shells remain the same and the number of electrons and protons increase as we move across the period to the right. The increased electrons and protons attract each other with greater force and hence the atomic size decreases. 

So the element on the left most will have the largest atomic radius. So the correct ans is Potassium. Potassium will have the largest atomic size among Potassium, Calcium and Scandium. 
svet-max [94.6K]2 years ago
8 0

Answer:

A.

Explanation:

Plato

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Is the sky actually blue?
Mkey [24]

Answer:

When we look at an arbitrary point in the sky, away from the sun, we see only the light that was redirected by the atmosphere into our line of sight. Because that occurs much more often for blue light than for red, the sky appears blue. Violet light is actually scattered even a bit more strongly than blue.

Explanation:

8 0
3 years ago
Which one of the following is not a valid expression for the rate of the reaction below? 4NH3 + 7O2 → 4NO2 + 6H2O Which one of t
Veseljchak [2.6K]

Answer : All of the above are valid expressions of the reaction rate.

Explanation :

The given rate of reaction is,

4NH_3+7O_2\rightarrow 4NO_2+6H_2O

The expression for rate of reaction for the reactant :

\text{Rate of disappearance of }NH_3=-\frac{1}{4}\times \frac{d[NH_3]}{dt}

\text{Rate of disappearance of }O_2=-\frac{1}{7}\times \frac{d[O_2]}{dt}

The expression for rate of reaction for the product :

\text{Rate of formation of }NO_2=+\frac{1}{4}\times \frac{d[NO_2]}{dt}

\text{Rate of formation of }H_2O=+\frac{1}{6}\times \frac{d[H_2O]}{dt}

From this we conclude that, all the options are correct.

3 0
2 years ago
How can one describe the bond between the two atoms of hydrogen to the one atom of oxygen within a molecule of water (h2o)?
Digiron [165]

There are O-H bonds in H2O. They have the intramolecular force of polar covalent bond.

4 0
3 years ago
Exactly one mole of an ideal gas is contained in a 2.00-liter container at 1,000 K. What is the pressure exerted by this gas?
levacccp [35]
Use PV =nRT

so P = nRT/V

= 1 mole(0.08205 L atm/K mol)(1000K) / 2 L

= 41 atm
7 0
2 years ago
Read 2 more answers
What net ionic equation describes the reaction when these solutions are mixed?
almond37 [142]
I think the correct answer from the choices listed above is option D. The net ionic equation that will describe the reaction of the reactants when mixed is expressed as:

<span>2PO43–(aq) + 3Ca2+(aq) → Ca3(PO4)2(s)
</span>
Hope this answers the question. Have a nice day.
7 0
3 years ago
Read 2 more answers
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