Answer:
Copernicus's model positioned the Sun at the center of the Universe, motionless, with Earth and the other planets orbiting around it in circular paths, modified by epicycles, and at uniform speeds. In a book called On the Revolutions of the Heavenly Bodies, Copernicus proposed that the Sun, not the Earth, was the center of the Solar System. Such a model is called a heliocentric system.
Answer:
O
2−
:
Explanation:
The atomic number of O=8=number of electrons
Number of electrons in O
2−
are 8+2=10
Electronic configuration will be 1s
2
2s
2
2p
6
Answer: B
Explanation: The mitochondria are vacuoles and ribosomes are in both plant and animal cell
