An atom is the simplest substance known and provides the building block from which all matter is composed. True or false

They carry out the exchange of gases as we breathe ( oxygen and carbon dioxide).

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later

The density would be 1.622

You can still be friends with each other. you don't have to date since he likes someone else. just stick to being friends for now