Answer:
Element X with atomic number 10 and atomic mass 21
Element Z with atomic number 10 and atomic mass 22
Explanation:
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- Isotopes of an element have the same electronic configuration.
- They share the same chemical properties
- They only differ in their masses.
So, Element X and Z with atomic number 10 which is their number of electrons are isotopes. Their mass number, 21 and 22 differs.
The electronic configuration of a chlorine ion in BeCl2 compound is
[2.8.8]^- (answer B)
chlorine atom gain on electron form Be to form chloride ions
chlorine atom has a electronic configuration of 2.8.7 and it gains one electron to form chloride ion with 2.8.8 electronic configuration
B.
The cynobacteria were already there without the oxygen, so that rules out A, and a lot of prokaryotes were anaerobic, so that rules out C. Finally, Photosynthesis does not require oxygen. Instead, Oxygen is a waste product of it. Therefore, it cannot be D. So, we are only left with B
Hoped this helped :D
False because there’s only 60% turbulence 20% heat 20% sound
Fuels are burned to produce energy, and your body breaks down the food to produce nutrients for your body.
