Flashcards
Chemistry
Cards in this deck (5)
- 1What 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.
- 2What 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.
- 3Why did Dmitri Mendeleev leave gaps in the first periodic table?To make predictions about the properties of undiscovered elements.
- 4Why 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.
- 5What 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.