it's the last one because it's depended on the rock layers
By taking hydrogen ions, certain bases directly lower the H+ than OH- concentration. Other bases break down to create hydroxide ions, which indirectly lowers the H+ concentration.
<h3>
What is the difference between acid and base?</h3>
H+ ion concentration is raised by an acid. A base is a chemical that, in an aqueous solution, produces hydroxide (OH-) ions, gives electrons, and receives protons. A donor of protons is an acid. A proton can enter a base. When dissolved in water, an acidic chemical compound produces a solution that has more H+ ion activity than clean water. A base is an aqueous material that releases hydroxide (OH-) ions, receives protons, or contributes electrons. A donor of protons is an acid. A base is a proton acceptor.
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Answer:
Mass of Rb-87 is 86.913 amu.
Explanation:
Given data:
Average mass of rubidium = 85.4678 amu
Mass of Rb-85 = 84.9117
Ratio of 85Rb/87Rb in natural rubidium = 2.591
Mass of Rb = ?
Solution:
The ration of both isotope is 2.591 to 1. Which means that for 2.591 atoms of Rb-85 there is one Rb-87.
For 100% naturally occurring Rb = 2.591 + 1 = 3.591
% abundance of Rb-85 = 2.591/ 3.591 = 0.722
% abundance of Rb-87 = 1 - 0.722= 0.278
84.9117 × 0.722 + X × 0.278 = 85.4678
61.306 + X × 0.278 = 85.4678
X × 0.278 = 85.4678 - 61.306
X × 0.278 = 24.1618
X = 24.1618 / 0.278
X = 86.913 amu
Number 18 is correct, number 19 is the particles speed up and the substance expands, and number 20 is decrease in volume
A positively charged nucleus with two protons and two neutrons hope this helps :)
