It's useful because it highlights structures in biological tissue.
Explanation:
Elements of group 1A are known as alkali metals. Elements of this group are lithium, sodium, potassium, rubidium, cesium, and francium.
All these elements are metals and every element of this group has 1 valence electron. So, in order to attain stability they will readily lose their valence electron.
Hence, elements of group 1A are very reactive.
On the other hand, elements of group 7A are also known as halogen group. Elements of this group are fluorine, chlorine, bromine, iodine, and astatine.
All these elements are non-metals and every element of this group has 7 valence electrons. So, in order to completely fill their octet these elements gain 1 electron from a donor atom.
Therefore, these elements are alo reactive in nature.
But the major difference between elements of group 1A and group 7A is that elements of group 1A are metals but elements of group 7A are non-metals.
That is true because the warm air goes up and the cold air comes down
Answer:i created brainly follow me and u grt all the answers u need
Explanation: