temperatures had to remain above 1 billion degrees in order for atoms to form. b. nebulae condensed and heated to become spinning accretionary disks, then protostars, then stars. c. the process of atom creation, termed Big Bang nucleosynthesis, produced all known natural elements. d. the Earth formed 4.5 billion years ago by the accretion of several small planetesimals.

The density of a liquid could be found by using

Which type of wave can travel without a medium

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.