Based on the periodic table, the element mendeleev called eka-manganese is now called technetium. Technetium<span> is a silvery-gray metal that tarnishes slowly in moist air. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
A substance can dissolve in another when they have thee same type of intermolecular interaction.
<h3>What is solubility?</h3>
The term solubility of a solute refers to the extent to which a solute dissolve in a solvent. We must know that a substance can dissolve in another when they have thee same type of intermolecular interaction.
Thus;
a) Octane (C8H18) mixes well with CCl4 because they are both non polar substances.
b) Methanol (CH3OH) is mixed with water in all ratios because the both are polar substances.
c) NaBr dissolves very poorly in acetone (CH3 ― CO ― CH3) because acetone is only slightly polar.
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Calcium fluoride.
Ca is metal, F is non-metal, so they form ionic bond.
Ca as metal can form only positive ion. Ca in the second group, so the charge of Ca ion is 2+. Ca²⁺
F is in the 17th group, so it has 7 electrons on the last level. It is non-metal, non-metal, so it has negative charge -(8-7)=-1. "8" because on the last level cannot be more than 8 electrons. F-ion is F¹⁻.
Ca²⁺ F¹⁻
Number of positive charges should be equal to number of negative charges,
Formula of calcium fluoride
CaF2.
2 atoms Fluorine bond with Calcium.
Besides producing hydrogen ions in water, all Arrhenius acids have a few things in common. They have pH values anywhere from 0 up to 7, they taste and smell sour and they will turn pH paper pink, red, or orange.
<h3>What Arrhenius acids?</h3>
A substance that raises the concentration of H+ ions in an aqueous solution is known as an Arrhenius acid. Traditional Arrhenius acids are highly polarized covalent substances that dissociate in water to form an anion (A-) and the cation H+.
Aqueous Arrhenius acids have distinguishing characteristics that serve as a useful definition of an acid. Acids can turn blue litmus red, produce aqueous solutions with a sour taste, and react with bases and some metals (like calcium) to generate salts. The Latin word acidus/acre, which means "sour," is where the word acid originates.
Although the precise definition solely refers to the solute, the term "acid" is sometimes used to refer to an aqueous solution of an acid that has a pH lower than 8.
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