Sodium has 11 electrons, and in its ground state, 8 of these electrons are located in the second principal energy level.
The total number of electrons in the second principal energy level of a sodium atom in the ground state can be determined by understanding the electron configuration of sodium.
Sodium (Na) has an atomic number of 11, which means it has 11 electrons. In the ground state, these electrons are distributed in various energy levels. The second principal energy level, often denoted as n=2, can hold a maximum of 8 electrons. The first energy level, n=1, can hold a maximum of 2 electrons.
To find the number of electrons in the second energy level, we first fill the first energy level with 2 electrons and then place the remaining 9 electrons in the second energy level. However, since the second energy level can only hold 8 electrons, sodium's electron configuration in the ground state is 2-8-1, where 2 electrons are in the first energy level, 8 electrons are in the second energy level, and 1 electron is in the third energy level.
So, there are 8 electrons in the second principal energy level of a sodium atom in the ground state.
For more such information on: energy level.
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(B) 100
(C) 15
(D) 25
(E) 30
MC₂H₄O₂ = 2 * 12 g/mol + 4 * 1 g/mol + 2 * 16 g/mol = 60 g/mol
c = 0.5 mol/L
V = 1 L
n = c * V
n = 0.5 mol/L * 1 L = 0.5 mol
m = n * M
m = 0.5 mol * 60 g/mol = 30 g/mol
answer E
(-_-(-_-)-_-)
Chemistry
The answer is: elements in the same group of periodic system have similar properties.
Dmitri Mendeleev published a periodic table of the chemical elements in 1869.
Mendeleev noted gaps in the table and predicted then undiscovered elements existed eka-silicon (germanium) and eka-boron (scandium).
For example, germanium discovered in 1886 and it had proporties as Mendeleev predicted.
There are 118 unique substances (elements) arranged on an amazing chart that reveals their hidden secrets to anyone who knows how to read it.
The first chemical element is hydrogen (atomic number is 1) and the last is oganesson (atomic number is 118).
Elements are scheduled in periodic table, ordered by their atomic number.