Creados entre los 800 y los 1500 o inventos que llevan de creación ese tiempo,puedes ser la pregunta un poco específica?
Helium is a chemical ELEMENT of the family of noble gases. Its chemical symbol is 'He' which has an atomic number of 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Although it doesn't really react under normal conditions, it is the second most abundant element in the universe.
Elements are pure substances that cannot be broken down any further.
Ba2+ and Cu2+, and Sr2+ and Li+
Answer:
Photosynthesis is the transformation of radiant energy to chemical energy. Plants take in water, carbon dioxide, and sunlight and turn them into glucose and oxygen. Called photosynthesis, one of the results of this process is that carbon dioxide is removed from the air.
Explanation: