Answer:
Francium is hypothesized to be the most reactive metal, but so little of it exists or can be synthesized, and the longest half-life of its most abundant isotope is 22.00 minutes, so that its reactivity cannot be determined experimentally.
Explanation:
Francium is an alkali metal in group 1/IA. All alkali metals have one valence electron. As you go down the group, the number of electron energy levels increases – lithium has two, sodium has three, etc..., as indicated by the period number. The result is that the outermost electron gets further from the nucleus. The attraction from the positive nucleus to the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive.
Experimentally speaking, cesium (caesium) is the most reactive metal.
Explanation:
For most folks, a thermometer reading around 98.6 degrees Fahrenheit (37 degrees Celsius) means their body temperature is normal. Now, two scientists have an idea why our bodies, as well as those of most other mammals, consistently run at that temperature : A toasty body temperature helps keep nasty fungal infections at bay.
"One of the mysteries about humans and other advanced mammals has been why they are so hot compared with other animals," said study co-author Arturo Casadevall, professor and chair of microbiology and immunology at Albert Einstein College of Medicine of Yeshiva. "This study helps to explain why mammalian temperatures are all around 98.6 degrees Fahrenheit."
Casdevall's previous work showed that the number of fungal species that can thrive and, therefore, infect an animal declines by 6 percent for every 1.8 degree F (1 C) rise in temperature. This, he claimed, is why reptiles , amphibians and other cold-blooded animals are susceptible to tens of thousands of fungal species, whereas only a few hundred types of fungi can harm humans and other mammals.
Is this a question or a statement?
Because the solid is soluble in water, it cannot be calcium fluoride.
This leaves us with either silver fluoride or potassium bromide, as both are soluble in water.
Upon addition of sodium sulfate, a white precipitate forms, confirming that the substance was silver fluoride as the precipitate are of silver sulfate.
This sums up solution for both the questions ;-)