According to the law of conservation of matter, which statement about chemical reactions is true?

atoms cannot be created or destroyed by chemical reactions.

every atom destroyed in a chemical reaction must be replaced.

energy is created as atoms are destroyed in chemical reactions.

atoms are created by some reactions and destroyed by others.

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

Temperature and pressure