Answer:
Anything that cannot be separated physically or chemically is an element.
<h3>Answer:</h3>
Rubidium (Rb)
<h3>Explanation:</h3>
Ionization Energy is defined as, "the minimum energy required to knock out or remove the valence electron from valence shell of an atom".
<h3>Trends in Periodic table:</h3>
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.
<h3>Conclusion:</h3>
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.
Answer:
As substances are cooled they contract
Explanation:
I found a similar problem to this as shown in the attached picture to helpme answer the problem. We use the M₁V₁ = M₂V₂ formula, wherein M₁ is the concentration of the original CuSO₄ solution, V₁ is the volume of CuSO₄ in the cuvette, M₂ is the concentration of Cu²⁺ in the cuvette, and V₂ is the total volume in the cuvette.
For cuvette 1:
M₁V₁ = M₂V₂
(0.06)(4 mL) = (M₂)(6+4 mL)
M₂ =
<em>0.024 M Cu²⁺</em>For cuvette 2:
M₁V₁ = M₂V₂
(0.06)(7 mL) = (M₂)(7+3 mL)
M₂ =
<em>0.042 M Cu²⁺</em>
If a salt has a pH less than 7, then it is an acid. All acids start with a H in there formula. The only compound that starts with an H from the listed options is HCOOK.
So the salt HCOOK has a pH<7
