Answer:
The first element in the periodic table is hydrogen.
Explanation:
Hydrogen has an atomic number of one, making it the first element of the periodic table. The atomic number of an element is just the number of protons in the nucleus, so hydrogen has one proton. The neutrons and electrons do not affect the atomic number. After hydrogen with one proton comes helium with two, lithium with three, beryllium with four, and so on.
Nucleic Acids are polymers made of nucleotideds
Answer:
friction
Explanation:
the resistance that one surface or object encounters when moving over another.
Food handler be unsuccessful to wash hands correctly after spending the restroom or when their hands become dirty.
Food handler coughs or sneezes on foodstuff.
Food handler traces or scratches wounds, cuts, or sores, and then touches food.
Food handler works though sick.
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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.
