Answer: pure substances.
Explanation:
The given substances are:
All what surrounds us, which has mass and occupies spaces, is matter. There are two kind of matter: pure substances and mixtures.
Pure substances have a uniform and constant composition. On the other hand, mixtures are combinations of two or more pure substances in any arbitratry ratio.
Pure substances may be elements or compounds. The elements are the substances conmposed by one only kind of atom. In the list of substances given, Li and O₂ are elements: all the atoms in Li are lithium, and all the atoms in O₂ are oxygen atoms.
Compounds are the chemical combination of two or more different kind of atoms. In the given list H₂O₂ and NaCl are compounds. As you see, H₂O₂ contains atoms of hydrogen and oxygen, chemically bonded, in a fixed ratio (2 atoms of hydrogen by 2 atoms of oxygen). And NaCl has atoms of Na (sodium) and Cl (chlorine), chemicaly bonded, in a fixed ratio (1:1).
There are only 118 known elements and you can find them in any modern periodic table. Therer are virtually infinitely many compounds since many different combinations of the elements can be attained.
Elements and compounds have in common that they are classified as pure substances.
Answer:The oxygen during photosynthesis comes from split water molecules. During photosynthesis, the plant absorbs water and carbon dioxide. After the absorption, the water molecules are disassembled and converted into sugar and oxygen.
Atoms
Explanation:
Chemical bonds results from the rearrangement of atoms in a chemical species.
It deals with the various attractive forces joining chemical species togethe.
- When atoms are re-arranged, they form chemical bonds that leads to production of new compounds.
- This is made possible by the exchange or sharing of electrons.
- The driving force for most interatomic bonding is the tendency to have completely filled outer energy levels like the noble gases.
- When atoms are re-arranged in compounds they lead to the production of chemical bonds.
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Ionic bonds brainly.com/question/6071838
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