Answer: helium(He)
Explanation: Helium has only 2 electrons in the outermost energy level, but all of the other elements in its column have eight.
Burning splint test
2H2 (g) + O2 (g) -> 2H20 (g) + heat
It’s a combustion reaction
Answer:
The answer is option a. The evaporation of water from the skin
Explanation:
An endothermic reaction is any synthetic reaction that retains heat from its environment. The ingested energy gives the enactment energy to the reaction to happen.
No new bonds formed, no bonds broken in this example. water molecules go from liquid to vapour (gas ), intermolecular bond exist between polar (-OH) molecules and energy is required to break these bonds during the change from liquid to gas. So, it is endothermic .
Remaining three above examples are exothermic. combustion of gas releases energy(exothermic). burninig of the candle exothermic because the energy released from the oxygen into carbon dioxide and water.oxidation of iron also exothermic
Answer:
it means compound A is <u>less</u> polar than compound B
Explanation:
It is sure that the more polar the solvent, the faster compounds elute, regardless of the compounds polarity. This means changing the solvent polarity cannot change the order compounds elute from a TLC or column. This may seem non intuitive, as it would seem that a polar solvent would move a polar compound farther than a nonpolar compound.
Tijuan mixed a solid and a liquid together in a beaker. He determined that a chemical change occurred. ... After a week, he observed that only solid salt remained in the cup and the mass had decreased I hope this helped! In some way
