Answer:
Wide melting point range - impure sample with multiple compounds
Experimental melting point is close to literature value - pure sample of a single compound
Experimental melting point is below literature value - impure sample with multiple compounds
Narrow melting point range - pure sample of a single compound
Explanation:
The melting point of substances are easily obtainable from literature such as the CRC Handbook of Physics and Chemistry.
A single pure substance is always observed to melt within a narrow temperature range. This melting temperature is always very close to the melting point recorded in literature for the pure compound.
However, an impure sample with multiple compounds will melt over a wide temperature range. We also have to recall that impurities lower the melting point of a pure substance. Hence, the experimental melting point of an impure sample with multiple compounds is always below the literature value.
Answer:
V
Explanation:
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow.
I think it's the minimum required energy to the reaction to occur
Answer: The box is moving downward with increasing speed.
Explanation:
VB theory does not indicate that the diatomic molecule He₂ is a viable species.
Helium has atomic number 2, it has 2 protons and 2 electrons.
Electron configuration of helium atom: ₂He 1s².
Helim (He) is a noble gas.
Noble gases (group 18) are in group 18: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn). They have very low chemical reactivity.
Noble gases have very stable electron configuration and does not need to gain electrons, only when they gain energy.
Valence bond (VB) theory explains chemical bonding.
Helium atom is stable and does not form molecule.
More about valence bond (VB) theory: brainly.com/question/23129240
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