Chemistry

Question	Answer
What is the difference between covalent bonds and ionic bonds?	Ionic bonds can happen between both metals and non - metals, whereas covalent bonds can only happen between non -metals.
What is an isotope?	Isotopes are atoms of the same element, they have the same atomic number but different mass numbers. They also have a different number of neutrons but the same number of protons.
Why did Dmitri Mendeleev leave gaps in the first periodic table?	To make predictions about the properties of undiscovered elements.
Why did people eventually believe Mendeleev?	He predicted the properties for an undiscovered element he called eka-aluminium, which was found to fit the element gallium very closely, when discovered in 1875.
What is the rule of electronic configuration?	2 in the first shell, 8 in the second and third, 18 in the fourth, then infinity in the fifth.

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	Created by rebekah eh. almost 7 years ago