(2) a molecular compound
(3) a metal
(4) a nonmetal
Answer: Option (1) is the correct answer.
Explanation:
An ionic compound is the compound which is composed of oppositely charged ions.
When an ionic compound is in a solid state, then oppositely charged ions are held together by strong electrostatic force of attraction. To break is force of attraction, high energy is required. That is why, ionic compounds do not conduct electricity as a solid.
Whereas in melted state, the ions are less tightly held and as a result they can move easily from one place to another. Also in melted state, ionic compounds act as strong electrolyte. Hence, they are able to conduct electricity.
On the other hand, molecular compounds are poor conductors of electricity and non-metals do not conduct electricity. Whereas a metal is a good conductor of electricity even in its solid state.
Thus, we can conclude that a substance that does not conduct electricity as a solid but does conduct electricity when melted is most likely classified as an ionic compound.
Answer:
Atomic radius of sodium = 227 pm
Atomic radius of potassium = 280 pm
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
Consider the example of sodium and potassium.
Sodium is present above the potassium with in same group i.e, group one.
The atomic number of sodium is 11 and potassium 19.
So potassium will have larger atomic radius as compared to sodium.
Atomic radius of sodium = 227 pm
Atomic radius of potassium = 280 pm
Answer:
The answer is B. Only synthesis.
Explanation:
Synthesis reactions are those in which two substances combine, giving rise to new substances. Breakdown of chemical bonds in reagents and formation of other bonds occurs, giving rise to new species.
A combustion is any reaction created between the combustible material and the oxidizer. Oxygen has the ability to combine with various elements to produce oxides. There are oxidations that are extremely slow, but when it is fast it is called combustion. That is why the oxidizer is oxygen, and the fuel is usually hydrocarbons (organic compounds made up of only carbon and hydrogen atoms). These usually go into combustion with ease.
In this case it is a synthesis, where two reagents, and , are combined to form a product, . It is not a combustion because despite having there is no hydrocarbon.
The potassium nuclei have been unstable and results in the spontaneous decay without any external force. Thus, option 3 is correct.
Potassium has been the metal of group 1 of the periodic table. It has been consisted of 19 protons and 20 neutrons in the nucleus.
The nuclei decay has been achieved when there has been loss of the protons in the nuclei, resulting in the radioactive isotopes.
The potassium nuclei have been unstable and results in the spontaneous decay without any external force. Thus, option 3 is correct.
Learn more about potassium nuclei, here: