Metals generally form cations, meaning they become positively charge - this positive charge is due to the loss of electrons.
Cs -137 has a half life of about 30 years. If 60 years pass, there is two half lives passed so 1/2 * 1/2= 1/4. Take 1/4 and multiply it with the mass given:
(1/4)*20mg=5mg left
Answer:
Any binary molecular compound of hydrogen and a Group 6A element above Selenium will be less acidic, so water and dihydrogen sulfide are less acidic in aqueous solution than hydrogen selenide.
Explanation:
Going down in a group increases the atomic radius and a greater atomic radius implyes greater ionic radius.
When ionization takes place in these compounds they yelds protons (hidrogen ion) and an lewis base (anion). The greater the ionic radius the greater its stability, thus the periodic tendency is increaing the acidity of binary hidrogen compounds when going down a group. On the other hand going up a group decreases acidity, so any molecular compound of hydrogen and a Group 6A element above Selenium will be less acidic, so water and dihydrogen sulfide are less acidic in aqueous solution than hydrogen selenide.
PCl₅ reacts upon contact with water to launch hydrogen chloride and supply phosphorus oxides. the primary hydrolysis product is phosphorus oxychloride PCl₅ + H₂O ========> POCl₃ + 2HCl.
Phosphorus trichloride appears as a colorless or slightly yellow fuming liquid with a pungent and irritating odor resembling that of hydrochloric acid. Causes severe burns to skin, eyes and mucous membranes.
Divide the mass of the material through its molar mass. The molar mass of a substance is the mass in grams of 1 mole of that substance. This mass is given via the atomic weight of the chemical unit that makes up that substance in atomic mass units.
One mole is described as the amount of substance containing as many number one entities atoms, molecules, ions, electrons, radicals, and lots of others. As there are atoms in 12 grams of carbon - 12(6. 023×10²³. The mass of one mole of a substance equals to its relative molecular mass expressed in grams.
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Answer is: <span>all of them are hard and dense metals.
Beryllium, magnesium,calcium and strontium are a</span>lkaline earth metals. The elements have very similar properties. Alkaline earth metals<span> have in common an outer s- </span>electron shell (two electrons). Strontium has greatest density of this four elements.
