Question

a device that records the electrical activity of the brain is an *
electron microscope.
electroencephalograph.
how long does stage i sleep last? *
up to 10 minutes
15 to 45 minutes
50 percent of the time spent asleep

Explanation:

• For the first question:
• An electron microscope is used to magnify very small objects (like cells or molecules) using electrons, not for recording brain electrical activity.
• An electroencephalograph (EEG) is specifically designed to record the electrical activity of the brain.
• For the second question:
• Stage I sleep is the lightest stage of non - REM sleep. It is a short - lived stage that typically lasts up to 10 minutes. Stage II sleep lasts 15 - 45 minutes. And 50 percent of the time spent asleep is not characteristic of Stage I sleep.

Answer:

• First question: electroencephalograph
• Second question: up to 10 minutes