What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:PLEASE MARK BRAINIEST
The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy. Today, this process uses instruments with a grating that spreads out the light from an object by wavelength. This spread-out light is called a spectrum. Every element — and combination of elements — has a unique fingerprint that astronomers can look for in the spectrum of a given object. Identifying those fingerprints allows researchers to determine what it is made of.
That fingerprint often appears as the absorption of light. Every atom has electrons, and these electrons like to stay in their lowest-energy configuration. But when photons carrying energy hit an electron, they can boost it to higher energy levels. This is absorption, and each element’s electrons absorb light at specific wavelengths (i.e., energies) related to the difference between energy levels in that atom. But the electrons want to return to their original levels, so they don’t hold onto the energy for long. When they emit the energy, they release photons with exactly the same wavelengths of light that were absorbed in the first place. An electron can release this light in any direction, so most of the light is emitted in directions away from our line of sight. Therefore, a dark line appears in the spectrum at that particular wavelength.
Explanation:
Answer:
Aristotle believes that all material substances are matter and form.
Explanation:
If you remember from the four causes, the matter is one cause and form is another cause. Substance theory says that substances are the ultimate things in the universe
