Answer:
<em>Carb</em><em>on</em><em> </em><em>dio</em><em>xide</em><em> </em>(co2)
<em>Wate</em><em>r</em><em> </em><em>(</em><em>H2O</em><em>)</em>
Effective nuclear charge is the charge felt by valence electrons of multi-electron atom taking into consideration the number of shielding electrons that surround the nucleus.
To calculate Z eff for electron we use this formula :
Z eff = Z - S where Z is the number of protons in nucleus and S is the average amount of electron density between the nucleus and electron in consideration
so Z eff = 17 - 10 (core electrons) = 7
So the correct answer is C
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.