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
<h3>Answer:</h3>
#1. Ca²⁺
# 2. Ca²⁺(aq) + SO₃²⁻(aq) → CaSO₄(s)
#3. 3Ag⁺(aq) + PO₄³⁻(aq) → Ag₃PO₄(s)
<h3>Explanation:</h3>
The question above concerns solubility of salts or ions in water.
The solution given contains Ag+, Ca2+, and Co2+ ions.
- In the first case, when Lithium bromide is added to the solution, there is no white precipitate formed.
- In the second case, the addition of Lithium sulfate results in the formation of a precipitate because of the Ca²⁺ in the solution combined with the SO₃²⁻ from lithium sulfate to form an insoluble CaSO₄.
- The net ionic equation for the reaction is;
Ca²⁺(aq) + SO₃²⁻(aq) → CaSO₄(s)
- From the solubility rules, all sulfates are soluble except BaSO₄, CaSO₄, and PbSO₄.
- In the third case, the addition of Lithium phosphate results in the formation of a precipitate because Ag⁺ ions in the solution combine with phosphate ions ( PO₄³⁻) from lithium phosphate to form an insoluble salt, Ag₃PO₄.
- The net ionic equation for the reaction is;
3Ag⁺(aq) + PO₄³⁻(aq) → Ag₃PO₄(s)
- According to solubility rules, all phosphates are insoluble in water except Na₃PO₄, K₃PO₄, and (NH₄)₃PO₄.
Answer:
C) It has a constant average kinetic energy
Explanation:
The average kinetic energy of the particles in a gas is directly proportional to the temperature of the gas, according to the equation.
k is the Boltzmann's constant
T is the absolute temperature of the gas
Therefore, temperature of a gas is a measure of the average kinetic energy of the particles.
In this problem, we are told that the gas is at constant temperature (and volume): therefore, according to the previous equation, this means that the average kinetic energy is also constant.
Answer:
metal to non metal ratio is 97/21 = 4.62 or
82.2% metals, 17.8% non metals
Explanation:
How do the numbers of metal and non-metal elements compare? Estimate an approximate percentage difference. (learning about the periodic table if...
of 118 elements in the periodic table , 21 are non metals (even H has metallic properties when approching 0 degrees K)
this means there ar 21 nonmetals and 118-21=97 metals.
Answer:
The second transformation is a rotation around (point) L.
Explanation:
Generally, a rigid transformation is used to change only the position of a figure while the shape remains the same. In order to map a triangle (ΔJKL) to another triangle (ΔMNQ), two rigid transformations were employed. In the first transformation, the vertex L was mapped to the vertex Q. Therefore, the second transformation will definitely involve the rotation around (point) L. This will complete the two rigid transformations.
