Answer:
All the members of a group of elements have the same number of valence electrons and similar chemical properties.
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior.
Bones affected in brachycephalic dogs are the jaw bones, and part of the skull.
The tiny holes in a sponges outer layer that take in water are called ostia, I believe. Hope it helps
Answer:
They were less influenced by the Sun and Gravitational interference of many smaller planets.
Explanation: