Answer:
option C= patterns
Explanation:
The periodic table is helpful to identify the element readily. All the elements are arranged properly. The elements with same physical and chemical properties are placed in same group and period. Periodic table is also helpful to predict the properties of those elements which are not discovered yet. This table is also very helpful to balance the chemical equations. The horizontal rows are called periods while vertical column are called groups. There are seven periods and eighteen groups are in periodic table.
Trends in periodic table:
As we move left to right in a period the atomic radius is decreases with increase of atomic number. The ionization energy goes to increases from left to right in period because of greater hold of nuclear charge on valance electron, so that's way more energy is required to overcome this charge and to make the atom ionic.
From left to right in period electron affinity and electronegativity also increases.
As we move top to bottom in group ionization energy decreases with increase of atomic number because of large atomic radius. The valance electron require less energy to move free. The electron affinity and electronegativity also decreases from top to bottom.
Answer:
52.15 × 10²³ atoms
Explanation:
Given data:
Number of moles = 8.66 mol
Number of atoms = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
1 mole = 6.022 × 10²³ atoms
8.66 mol × 6.022 × 10²³ atoms / 1mol
52.15 × 10²³ atoms
Answer:
0.21 M. (2 sig. fig.)
Explanation:
The molarity of a solution is the number of moles of the solute in each liter of the solution. The unit for molarity is M. One M equals to one mole per liter.
How many moles of NaOH in the original solution?
,
where
is the number of moles of the solute in the solution.
is the concentration of the solution. 
for the initial solution.
is the volume of the solution. For the initial solution, 
for the initial solution.
.
What's the concentration of the diluted solution?
.
- is the number of solute in the solution. Diluting the solution does not influence the value of .
for the diluted solution. - Volume of the diluted solution:
.
Concentration of the diluted solution:
.
The least significant number in the question comes with 2 sig. fig. Keep more sig. fig. than that in calculations but round the final result to 2 sig. fig. Hence the result: 0.021 M.
Answer:
D.Lowering the temperature is the best option.
Explanation:
The value of equilibrium constants aren't changed with change in the pressure or concentrations of reactants and products in equilibrium. The only thing that changes the value of equilibrium constant is a change of temperature.
In the reaction below for example;
A + B <==>C+D
If you have moved the position of the equilibrium to the right (and so increased the amount of C and D), why hasn't the equilibrium constant increased?
Let's assume that the equilibrium constant mustn't change if you decrease the concentration of C - because equilibrium constants are constant at constant temperature. Why does the position of equilibrium move as it does?
If you decrease the concentration or pressure of C, the top of the Kc expression gets smaller. That would change the value of Kc. In order for that not to happen, the concentrations of C and D will have to increase again, and those of A and B must decrease. That happens until a new balance is reached when the value of the equilibrium constant expression reverts to what it was before.
