When forces are in equilibrium.
<span>A rock lying on the ground exerts a force on the eartth equal to its mass times acceleration due to gravity. </span>
<span>The earth exerts an identical reactionary force stopping the rock from moving. </span>
<span>A force is being applied but there is no work being done.</span>
Answer:
0.868M Cu⁺
Explanation:
The reaction is:
KMnO₄ + 5Cu⁺ + 8H⁺ → 5Cu²⁺ + Mn²⁺ + K⁺ + 4H₂O
<em>Where 1 mol of KMnO₄ reacts with 5 moles of Cu⁺</em>
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3.30x10⁻²L of 0.132M KMnO₄ are:
3.30x10⁻²L × (0.132mol KMnO₄ / L) = <em>4.356x10⁻³mol KMnO₄</em>
As 1 mol reacts with 5 moles of Cu⁺, moles of Cu⁺ are:
4.356x10⁻³mol KMnO₄ × (5mol Cu⁺ / 1mol KMnO₄) = <em>0.02178moles Cu⁺</em>
As these moles are in 2.51x10⁻²L, the starting concentration of the Cu⁺ solution is:
<em>0.02178moles Cu⁺ / </em>2.51x10⁻²L = <em>0.868M Cu⁺</em>
The smallest and the basic particle of a chemical element is said to be an atom. It is made up of three subatomic particles that is electrons, protons and neutrons. The neutrons and protons are present in the nucleus of an atom whereas electrons are present in the orbits around the nucleus of the atom. There are several shells in the orbital depending on the atomic number. The electrons which are present in the outermost shell are said to be valence electrons.
They can be determined by the electronic configuration of the element.
The atomic number of strontium, is 38. The electronic configuration of strontium, is:
From the electronic configuration it is clear that the outermost shell of strontium, is . So, the number of valence electrons in strontium, is 2.
Hence, there are 2 valence electrons in an atom of strontium ().