The correct answer is D.
The cell membrane is a semi permeable structure, that is, it allows some substances to move to and from the cell but it impedes the movement of other substances. Some proteins are embedded in the membrane of the cell, these serve as carriers for substances which has to enter the cell but which can not pass through the semi permeable membrane of the cell.
Typical methods of classroom scientific communication depending on the level of study could include a range of these activities which have been listed in the answers. However, at the elementary, middle, and high school levels it would be safe to argue that the typical methods of communication are B) lectures, lab reports, term papers, and poster presentations. At higher levels would some of the other methods of communication be used such as scientific journals, oral presentations, lectured, conferences, etc.
Answer:
B) The first shell only holds 2 electrons so the 3rd electron had to go in the second shell.
Explanation:
Electrons fill up from smallest to largest, the first electron shell only holds 2 electrons, so the remaining electron had to go to the second shell.
50-80 bpm is the average adult resting
heart rate