Why are the platypus, brown bear, lion, and house cat thought to be related to each other?

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Sequence how oxygen accumulated in the atmosphere and the effect it had on life by completing the flowchart

1. you serve a volleyball with a mass of 2.1 kg. the ball leaves your hand with a speed of 30 m/s. the ball has energy. calculate it. 2. a baby carriage is sitting at the top of a hill that is 21 m high. the carriage with the baby weighs 12 n. the carriage has energy. calculate it. 3. a car is traveling with a velocity of 40 m/s and has a mass of 1120 kg. the car has . calculate it.