Answer:
Elements having same valence electrons are placed in <u>same group.</u>
Explanation:
First, let's start with some basic concepts of modern periodic table:
1. Modern Periodic table : It is the arrangement of element in the increasing order of their atomic numbers
The Modern periodic table is divided into Periods and groups .
Periods : These are the horizontal rows. There are seven periods in the periodic table . Period 1 has 2 element. Period two and three has 8 elements , period 4 and 5 have 18 elements and the period 6 and 7 have 32 elements.
Same period have same number of atomic orbital(Shell)
Group : The group is the vertical columns . There are 18 groups in the modern periodic table.Those element which have same group number will also have same number of electron in their outermost shell. The number of electron in the outermost shell determines the valency of the element.
So, elements showing same valency are placed in same group.
All alkali are place in group 1 and have 1 valance electron in the outermost shell
The second volume : V₂= 0.922 L
<h3>
Further explanation
</h3><h3>Given
</h3>
7.03 Liters at 31 C and 111 Torr
Required
The second volume
Solution
T₁ = 31 + 273 = 304 K
P₁ = 111 torr = 0,146 atm
V₁ = 7.03 L
At STP :
P₂ = 1 atm
T₂ = 273 K
Use combine gas law :
P₁V₁/T₁ = P₂V₂/T₂
Input the value :
0.146 x 7.03 / 304 = 1 x V₂/273
V₂= 0.922 L
Answer:
Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions ). These forces are weak compared to the intramolecular forces, such as the covalent or ionic bonds between atoms in a molecule.
Importance:
Intermolecular forces are important because they determine the physical properties of substances. Many of the life-sustaining properties of water such as its high heat capacity are a result of the hydrogen bonding capabilities it has and are thus due to intermolecular forces.
These are dissolved in water to form colourless solutions, and then mixed together. This mixing leads to a double displacement reaction, essentially resulting in the metals 'swapping' their places in the two compounds, producing lead (II) iodide, and potassium nitrate.
Answer: 5
Explanation: add up all the electrons and it will amount to 23. Arranging by the old model for electronic configuration, we have : 2, 8, 8, 5
The last number being 5 represent its valence electron
