He proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another.
Because people make those substance out of other things
<u>Answer:</u>
Those cells that develop differently are referred to Specialised Cells.
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</u><u>Explanation:</u>
Specialised cells are the one that is assigned to perform a specific role. Every specialised cell in the body is assigned to do their own job. The special features in them help them to perform their functions effectively.
Examples of specialised cells are- red blood cells (they are responsible to carry oxygen in the body), nerve cells (specialises in transmitting electrical signals) and muscle cells (brings body parts together).
The choices for this problem are bismuth, Bi; platinum, Pt; selenium, Se; calcium, Ca and copper, Cu. I think the correct answer would be selenium. The melting point of bismuth is at a temperature of 544.4 Kelvin. At a temperature of 525 K, it would exist as solid. Platinum melts at 2041.1 K. At 525 K, platinum would be in solid form. Selenium has a melting point at 494 K so that at a temperature of 525 K, it would exist in its liquid state. Calcium has a melting point of 1112 K so it would exist as solid at 525 K. Copper has a melting point at 1358 K, so it would still exist as solid at a temperature of 525 K. Therefore, the answer would only be selenium.
