Answer:
A
Explanation:
The purpose of the periodic table was to organize elements as they were discovered into periods and groups, according to their properties. It was not just a naming of elements, as a list.
Answer:
a)Atomic number
Explanation:
Element symbol signifies the element. For eg, Na is sodium. Mass number is the sum of protons and neutrons of an atom of an element. Atomic mass is the molar mass of the given element. Finally, atomic number is unique to each element because it signifies the number of protons of that element. EACH ELEMENT has their UNIQUE number of protons. For eg, atomic number of hydrogen is 1 because it has 1 proton, NO OTHER ELEMENT HAS ATOMIC NUMBER 1 because NO OTHER ELEMENT HAS 1 proton.
When it is acted upon by an outside force
A straight line on a distance va time graph represents constant speed
