Answer:
4
Explanation:
Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms.
Answer:
water
Explanation:
Water puts out fire by creating a barrier between the fuel source and the oxygen source (it also has a cooling effect which has to do with the energy required to convert liquid water into water vapor). It does this because it is a completely, 100% oxidized material. It simply cannot oxidize any further so it will not “burn”. This smothers the fire. The same thing would happen if you used the ashes that remained after a completely spent fire. Or, as I mentioned before, CO2.
Answer:
you should always wash your hands regularly and avoidance of shaking hands
Mycobacterium bacteria is rod shaped. The specific species that caused TB is mycobacterium tuberculosis.
Answer:
They used artificial selection
Explanation:
Breeding animals who had desirable or good traits. For example, they bred cows who produced the most milk and plants that produced the most vegetables. :))
