Mendeleev’s arrangement of elements in the periodic table was based on the observations and experiments of his predecessors who studied mass and properties of elements is TRUE.
<u>Explanation:</u>
In Mendeleev’s periodic table, elements were ordered according to their atomic masses. This is the fundamental property on which Mendeleev's periodic table is based on.
Mendeleev has also formulated a periodic law which states that the properties of elements are the "periodic function of their atomic masses". However, due to the anomalies that were created in his periodic table, we don't use this periodic table and prefer modern periodic table that is based on property of atomic number.
A molecule of a compound is composed of at least two types of atoms.
Explanation:
A molecule is defined as when two or more atoms of an element combine together by the bonds by sharing the electrons as O^2 (oxygen molecule)
A compound is a molecule when two different types of atom joined by chemical bonds as covalent, ionic or coordinate bonds as NH^3 ( ammonia)
<span>You have to use an activity series and then predict which metal by itself will replace the metal inside of the compound. These all appear to be single replacement reactions.</span>
A chemical formula shows the atoms and their respective quantity in a compound or molecule. The chemical formula CO2 reads as carbon, one atom, oxygen, two atoms. Another example is H2O (water).
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