On Earth it is relatively rare—5.2 ppm by volume in the atmosphere. Most terrestrial helium<span> present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium, although there are other examples), as the alpha particles emitted by such decays consist of </span>helium<span>-4 nuclei.</span>
In exothermic reactions, there is a release heat and the replacement of weak bonds with stronger ones.
Answer: Mendeleev improve newlands periodic table because he swapped the order of some elements if that fitted their properties better.
Explanation: I hope this helps!... :)
Answer:
Explanation:
Saturated hydrocarbons are defined as the hydrocarbons in which a single bond is present between carbon and carbon atoms.These are called as alkanes. The general formula for these hydrocarbons is
Unsaturated hydrocarbons are defined as the hydrocarbons which have double or triple covalent C-C bonds. They are known as alkenes and alkynes respectively. The general formula for these hydrocarbons is
and
.
1. Propyne is
and is an unsaturated hydrocarbon.
2. Methane is
and is a saturated hydrocarbon
3. Nonane is
is a saturated hydrocarbon.
4. Methyl is
and is a saturated alkyl group.
Answer:
Here's what I get
Explanation:
The reaction is an E1 elimination of an alcohol to form an alkene. It has three steps:
1. Protonation
The alcohol is protonated with aqueous sulfuric acid to convert it into a better leaving group.
2. Loss of the leaving group
A water molecule leaves in a unimolecular process to form a stable 3° carbocation.
3. Loss of an α-hydrogen
A water molecule removes an α-hydrogen, forming 2-methylpropene and regenerating the original hydronium ion.