1, 2, 5 are figures that have patterns formed from four lines curved in a concave direction. 3, 7, 8 are figures that have patterns formed from four lines curved in a convex direction. 4, 6, 9 are figures that have patterns formed from these straight lines.
Atoms of the same element can have same atomic number and number of electrons since, the atomic number is the number of protons and the number of protons and eectrons are the same in an element.
Hence, the atoms of the same element may differ in their atomic mass since it depends on the number of neutrons it holds and such atoms are called isotopes.
The term for classifying and grouping organisms is Taxonomy. It is the science of defining and naming groups of biological organisms on the basis of shared characteristics.
Centrifugal force is the fictitious force that pulls out from the center on the body we feel while moving in the circular path. It increases with the rate of rotation of the axis i.e, acceleration of the body.