<span>The </span>abundance of a chemical element<span> is a measure of the </span>occurrence<span> of the </span>element<span> relative to all other elements in a given environment. Abundance is measured in one of three ways: by the </span>mass-fraction<span> (the same as weight fraction); by the </span>mole-fraction<span> (fraction of atoms by numerical count, or sometimes fraction of molecules in gases); or by the </span>volume-fraction<span>. Volume-fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole-fraction for gas mixtures at relatively low densities and pressures, and </span>ideal gas<span> mixtures. Most abundance values in this article are given as mass-fractions.
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Answers:
(a) 1s² 2s²2p³; (b) 1s² 2s²2p⁶ 3s²3p⁶ 4s²3d²; (c) 1s² 2s²2p⁶ 3s²3p⁵
Step-by-step explanation:
One way to solve this problem is to add electrons to the orbitals one-by-one until you have added the required amount.
Fill the subshells in the order listed in the diagram below. Remember that an s subshell can hold two electrons, while a p subshell can hold six, and a d subshell can hold ten.
(a) <em>Seven electrons
</em>
1s² 2s²2p³
There are two electrons in the 2s subshell and three in the 2p subshell. The remaining two electrons are in the inner 1s subshell.
(b) <em>22 electrons
</em>
1s² 2s²2p⁶ 3s²3p⁶ 4s²3d²
There are two electrons in the 4s subshell and two in the 2p subshell. The remaining 18 electrons are in the inner subshells.
(c) <em>17 electrons</em>
1s² 2s²2p⁶ 3s²3p⁵
There are two electrons in the 3s subshell and five in the 2p subshell. The remaining 10 electrons are in the inner subshells.
Answer:
The answer is "
"
Explanation:
Given:
Molarity= number of moles
because it is 1 Liter

therefore,
it takes 20 mL of Tris.


So, take 
Answer:
7 orbitals
Explanation:
An f sublevel has 7 orbitals
There are 2 electrons in the overlapping region.
Chlorine is the second member of the halogen group which are form of family of elements that resemble one another very closely.
The electronic configuration of chlorine shows the arrangement of chlorine electrons within it's atom.
At the outer most shell of the atom is seven electrons, therefore requires only one electron each to attain the octet arrangement.
The overlapping of the orbitals indicates the chemical bond formed by sharing of electrons between atoms called covalent bonding.
To complete it's outer most shell, it will need to share electron with another chlorine atom.
Therefore, there are 2 electrons in the overlapping region.
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