<span>The key difference between Mendeleev and modern periodic table is that Mendeleev’s periodic table was based on the increasing atomic masses while the modern periodic table is based on the increasing atomic numbers. Let us see here what is Mendeleev periodic table and what is modern periodic table, and then compare both to understand the difference between both periodic tables. Mendeleev is the pioneer of the modern periodic table, though a numerous number of changes had been made to the old version of the periodic table. Both of these attempts are equally important to the scientific community; because without an invention of the periodic relationship in elements, the modern developments in Science would not reach a development era as today. Before the invention of Mendeleev’s classification, there were several attempts made by several chemists, but their periodic laws were inadequate to apply for all the elements. The modern periodic table is so advantageous for the development in the Science.</span>
1. B. Calcium is a chemical element that can be found as Ca on the periodic table.
2 A. Heterogeneous mixture. Pizza is not uniform and is a variation of cheese, bread, and toppings that aren't mixed completely together.
3. B. Carbon Monoxide, or CO, is a chemical compound, a combination of 2 or more chemical elements.
Answer: Multiply the mass by the inverse of molar mass, and then multiply by Avogadro's number.
Explanation: Convert the mass to moles, multiply the number of moles by the ratio of the number of atoms or ions to one mole, multiply by Avogadro's number.
Answer:
best answer is D
Explanation:
if element has even number then protons and neutrons are same but if element has odd number then we should add 1 number in number of protons to know neutrons. but this rule is not work in 4 element that element are argon, nitrogen, hydrogen and one other
It will have 12 neutrons.