An atom of which element has the largest atomic radius?
1 answer:
Answer:
B) Be
Explanation:
Across the period (going from left to right of the periodic table), the atomic radius decreases. Beryllium is located further on the left of the periodic table compared to the other elements in the option and thus it has the largest atomic radius.
<u>Explanation of trend</u><u>:</u>
Across the period, the number of protons and electrons increases in the atom. Electrons are added to the valence shell, hence the electrons added are not able to shield the increased nuclear charge well. (Since shielding effect is most effective when core electrons shield the valence electrons) Therefore, the effective nuclear charge (ENC) increases. As ENC increases, valence electrons are increasingly attracted to the nucleus. They are drawn closer to the nucleus, and so the atomic radius decreases across the period.
What is ENC?
ENC is the net nuclear charge acting on the valence electron (since the valence electron experiences electrostatic forces of attraction by the positively charged protons in the nucleus, and an electron-electron repulsion force by the core electrons)
➣ ENC
= nuclear charge (atomic no.) - shielding constant (no. of core electrons)
See diagram: black arrow represents the shielding effect (also known as electron-electron repulsion), while the orange arrows represent the nuclear charge (electrostatic forces of attraction)
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Answer:
of neon
at
and
(the second choice) would contain an equal number of gas particles as
of
at
and
(assuming that all four gas samples behave like ideal gases.)
Explanation:
By Avogadro's Law, if the temperature and pressure of two ideal gases is the same, the number of gas particles in each gas would be proportional to the volume of that gas.
All four gas samples in this question share the same temperature and pressure. Hence, if all these gases are ideal gases, the number of gas particles in each sample would be proportional to the volume of that sample. Two of these samples would contain the same number of gas particles if and only if the volume of the two samples is equal to one another.
The second choice, of neon
at
and
, is the only choice where the volume of the sample is also
. Hence, that choice would be the only one with as many gas particles as
of
at
and
.
Explanation:
Given the mass of HCl is ---- 0.50 g
The volume of solution is --- 4.0 L
To determine the pH of the resulting solution, follow the below-shown procedure:
1. Calculate the number of moles of HCl given by using the formula:
2. Calculate the molarity of HCl.
3. Calculate pH of the solution using the formula:
Since HCl is a strong acid, it undergoes complete ionization when dissolved in water.
Thus,
Calculation:
1. Number of moles of HCl given:
2. Concentration of HCl:
3. pH of the solution:
Hence, pH of the given solution is 2.47.
Answer:
The answer is "".
Explanation:
Please finds the complete question in the attached file.
The mass of acetone to be weighed is
