Answer: Acids from the lichens growing on the rock breaks down the rock into soil
Explanation:
Answer:
Animal cell lacks chloroplasts and a cell wall
Explanation:
Unlike animal cells, plant cells have chloroplasts and a cell wall. In a plant cell, the chloroplasts work to use photosynthesis in order to turn light into energy for the plant cell. Animal cells do not utilize light energy, and therefore do not carry out photosynthesis and do not have chloroplasts.
Additionally, the plant cell has a protective cell wall and a cell membrane, while animal cells only have a cell membrane. This is because the plant cells' cell wall provides additional strength and protection against outside factors, such as osmosis.
Oxygen:
Atomic no. = 8(from periodic table)
⇒1s^2 2s^2 2p^4
But it is O^2-
There are 2 more electrons
=>1s^2 2s^2 2p^6
Voila!
Answer: Most of the stars in the universe are main sequence stars — those converting hydrogen into helium via nuclear fusion. A main sequence star may have a mass between a third to eight times that of the sun and eventually burn through the hydrogen in its core. Over its life, the outward pressure of fusion has balanced against the inward pressure of gravity. Once the fusion stops, gravity takes the lead and compresses the star smaller and tighter.
Temperatures increase with the contraction, eventually reaching levels where helium is able to fuse into carbon. Depending on the mass of the star, the helium burning might be gradual or might begin with an explosive flash.
Atomic number refers to the number of protons within the nuclei of an element's atoms (and therefore the number of electrons) while mass number refers to the number of protons and neutrons within the nucleus.
