Why are there only two elements in the first period of the periodic table? (1 point) O because the first two elements both start with H and are grouped together
o
because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by
number of orbits
O because each row increases in atomic mass by a specific number, so anything over five is in the second row
Obecause the next elements have other things in common and they need to be arranged together
M

In 1859, charles darwin published the first edition of on the origin of species, which explained his observations of various groups of animals that showed great similarities but minor differences. darwin concluded that if a population of one species separates into two different populations that live in separate locations, then over the course of many generations the different populations can develop into different species. this idea predicted many future biological findings and became the basis of modern biology. darwin’s explanation for why different species exist is best described as a(n) law. theory. inquiry. hypothesis.