(2) increases
(3) remains the same
As the elements in Group 17 are considered in order of increasing atomic number, the chemical reactivity of each successive element decreases.
The impetus for a chemical substance to undergo a chemical reaction, either by itself or with other materials, with an ease and overall release of energy is referred to as reactivity.
Group 17 are the halogens group and on moving from top to bottom across that group atomic size of the atoms increases due to the increase in the number of energy shells. As a result of which it decreases the affect of nuclear attraction force to the outer most valence shell decreases.
Hence, reactivity decreases.
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The hydrogen atom has only one electron which is present in the first shell.
We know that first shell can hold a maximum of two electrons so due to incomplete valance shell hydrogen atom is reactive and make covalent bond with other reactive atoms. This bonding will complete its valance shell and finish its reactive nature. In the second shell and other shells can hold 8 electrons so we can conclude that hydrogen has one valance electron.
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Rubidium (Rb)
Ionization Energy is defined as, "the minimum energy required to knock out or remove the valence electron from valence shell of an atom".
Along Periods:
Ionization Energy increases from left to right along the periods because moving from left to right in the same period the number of protons (atomic number) increases but the number of shells remain constant hence, resulting in strong nuclear interactions and electrons are more attracted to nucleus hence, requires more energy to knock them out.
Along Groups:
Ionization energy decreases from top to bottom along the groups because the number of shells increases and the distance between nucleus and valence electrons also increases along with increase in shielding effect provided by core electrons. Therefore, the valence electrons experience less nuclear attraction and are easily removed.
Given elements belong to same group hence, Rubidium present at the bottom of remaining elements will have least ionization energy due to facts explained in trends of groups above.
The mass percent of a solution is calculated by dividing the mass of the solute by the total mass of the solution and multiplying by 100%. In this case, the solute is Na₂CO₃ and the solvent is H₂O. The calculation yields a mass percent of 6% for Na₂CO₃ in the solution.
To calculate the mass percent of a solution, we need the mass of the solute and the mass of the solution (which is the sum of the masses of the solute and the solvent). In your given solution, you have 15 g of Na₂CO₃ (solute) and 235 g of H₂O (solvent). Therefore, the total mass of the solution is 15 g (Na₂CO₃) + 235 g (H₂O) = 250 g.
Now, to find the mass percent of Na₂CO₃ in the solution, we use the following formula:
Mass percent = (mass of solute / total mass of solution) × 100%
Substitute the known values into the formula, we get:
Mass percent = (15 g / 250 g) × 100% = 6%
So, the mass percentage of Na₂CO₃ in the H₂O solution is 6%.
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Answer:
Heat is transferred from the warmer block to the cooler block
Explanation:
Heat transfer by conduction involves two or more solids. The heat generally moves from a part at higher temperature to one with a lower temperature.
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Sea arch
Sea cave
Sea cliff
Sea stack
The answer is "sea stack" or the fourth option. Sea stacks are tall pieces of land in the ocean that had been eroded all the way to look like a stack of rocks. Sea stacks look like this:
Hope this helps!