F BLOCK is the block on the period table that contains the actinide series of elements.
Actinide series of elements are two rows under the periodic table which include Lanthanide series and Actinide series. These are all radioactive elements and all of these are not not found in nature. All these are included in F block element.
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Answer :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and the unpaired electrons present in the molecule.
The given molecule is, 
Beryllium has '2' valence electrons and fluorine has '7' valence electrons. Beryllium is the central atom and fluorine is the terminal atom.
Total number valence electrons in = 2 + 2(7) = 16
According to the Lewis-dot structure, there are '4' number of bonding electrons and 12 number of non-bonding electrons (lone-pair).
The Lewis-dot structure is shown below.
Answer:
At 0.58 L of 0.540 M NaOH solution contain 12.5 g NaOH.
Explanation:
Given data:
At volume = ?
Mass of NaOH = 12.5 g
Molarity of solution = 0.540 M
Solution:
First of all we will calculate the number of moles of sodium hydroxide.
Number of moles = mass/molar mass
Number of moles = 12.5 g / 40 g/mol
Number of moles = 0.3125 mol
Volume of NaOH:
Molarity = number of moles / volume in L
Now we will put the values.
0.540 M = 0.3125 mol / volume in L
volume in L = 0.3125 mol / 0.540 mol/L
volume in L = 0.58 L
Answer:
1.26 M
Explanation:
The ion nitrate is NO₃⁻ and the Barium is from group 2 so it forms the ion Ba²⁺, so the barium nitrate has the formula: Ba(NO₃)₂. The molar masses are: Ba: 137 g/mol, N = 14 g/mol, O = 16 g/mol, so the molar mass of barium nitrate is:
137 + 2x(14 + 3x16) = 199 g/mol
The number of moles is the mass divided by the molar mass, so:
n = 25.1/199 = 0.126 mol of Ba(NO₃)₂
In 1 mol of the salt, there are 2 moles of NO₃⁻, so the number of moles of nitrate is 0.252 mol. Nitrates formed with ammonium (that can react when the solid dissolves) and with elements from group 1 and 2 are completely soluble in water. So, the moles of nitrate will remain 0.252 mol.
The molarity is the number of moles divided by the volume (0.2 L):
[NO₃⁻]= 0.252/0.2 = 1.26 M
