Lithium and beryllium are both located in period 2 of the periodic table, in group 1 and group 2, respectively.
For both these elements, the outermost electrons are located on the second energy level in the 2s-subshell. However, these outermost electrons. which ultimately determine the atomic radius, are closer to the nucleus in beryllium's case.
That happens because beryllium has a higher effective nuclear charge Zeff than lithium.
The effective nuclear charge is simply a measure of the net positive charge that affects the outermost electrons in an atom.
In lithium's case the outermost electron is being screened from the nucleus by two core electrons. The same is true for the two outermost electrons in beryllium, they are screened by two core electrons.
However, beryllium has 4 protons in its nucleus, as opposed to 3 protons which are present in the nucleus of a lithium atom.
This means that the nucleus of a beryllium atom will pull on the outermost electrons with more force, effectively compressing the distance between itself and these electrons.
That is why lithium has a larger atomic radius than beryllium. That's atomic radius decreases as you move from left to right across a period.
7.23 Explain why the atomic radius of Be is smaller than that of Li.
a) Why is the Li+ radius so much smaller than the radius of the neutral Li atom? b) Why is the F- radius so much larger than the neutral F atom? b) Which transition involves the emission of less energy in the H atom, an electron moving from n=4 to n=3 or an electron moving from n=3 to n=2?
1. Explain why the atomic radius of Ga is smaller than Ca. You cannot merely state the trend. You must explain using Z and shielding. 2. Explain why the ionization energy of Ga is less than Ca. 3. Draw the best Lewis structures for the following species. Ensure you make the dots very clear to see. Show nonzero formal charges on the correct atoms. a) SbI4- anion b) COCl2 c) XeOF4 4. For the above species, draw the molecular geometry...
answer a b or c Why is the atomic radius of magnesium ion much smaller than that of a neutral charged magnesium atom? (See the atomic radius graph) The magnesium ion's electrons require less space. No electrons are lost, they move to unoccupied spaces about the nucleus. The magnesium ion has fewer principle quantum energy levels, this causes a decrease in atomic radius. The magnesium ion has a higher Z-effective nuclear charge. The magnesium ion has more principle quantum energy...
In methyl mercaptan (CH3SH), the C-H bond is smaller than the S-H bond. Why? A. Because sulfur has a smaller bonding atomic radius than carbon B.Because hydrogen has a smaller bonding atomic radius than sulfur C. Because hydrogen has a smaller bonding atomic radius than carbon D. Because carbon has a smaller bonding atomic radius than sulfur E. Because carbon has a smaller bonding atomic radius than hydrogen
Why does Ca have a bigger atomic radius than Na? The periodic trend for atomic radius says that the lower and more to the left an element is, the greater it's atomic radius. In our case, Na is more to the left, but the Ca is lower down. How do we reconcile this?
The element with the largest atomic radius is B Li OF Na
The ionic radius of Cs+ is ________ than the atomic radius of Cs, and the ionic radius of I- is ________ than the atomic radius of I.
which has smaller ionization of Li Or Be explain using Zeff
ULF C. Explain the reasons behind these 'atomic/ionic size differences: (15) i) atoms decrease in radius across a period ii) Group Il cations are smaller than the parent atom iii) anions are larger than the parent atom
D Question 10 Why is Bra smaller atom than As? Br is actually larger than As because it has more protons. As is larger because it has more protons and electrons. Br has more protons to pull the electrons in closer. Br is smaller because it has less protons and electrons making it smaller. Br is actually larger than As because it has a larger atomic mass. Question 11 Explain why metals have lower ionization energy than nonmetals. No answer...