The melting point is the temperature a substance must reach to go into its liquid phase (or solid) and a boiling point is the temperature a substance must reach to go into its gas phase (or liquid). For example, water must be 0ºC to melt or freeze and 100ºC to boil.
Answer:
This question is incomplete
Explanation:
This question is incomplete but some general explanation provides a clear answer to what is been asked in the question.
An ionic/electrovalent compound is a compound whose constituent atoms are joined together by ionic bond. Ionic bond is a bond involving the transfer of valence electron(s) from an atom (to form a positively charged cation) to another atom (to form a negatively charged anion). The atom transferring is usually a metal while the atom receiving is usually a non-metal.
For example (as shown in the attachment), in the formation of NaCl salt, the sodium (Na) transfers the single electron (valence) on it's outermost shell to chlorine (Cl) which ordinarily has 7 electrons on it's outermost shell but becomes 8 after receiving the valence electron from sodium. It should also be noted that Na is a metal while Cl is a non-metal.
Answer:
B and D as well
Explanation:
All the electronic configuration of the elements of B end on s sub shell.
S energy level sub shell can hold 2 electrons and since Be, Mg, Ca Sr end in s.
We can say, they have same valence electrons, i.e 2 electrons.
The water cycle is one interaction between the geosphere and the cryosphere.