The statement "The number of protons in an atom determines its chemical properties" is True.
The number of protons in the nucleus of an atom is fundamental in determining the chemical properties of an element. This number is known as the atomic number. Here's why it's so crucial:
- Identity of the Element: The atomic number, which is the number of protons in the nucleus, uniquely identifies an element. For example, hydrogen has 1 proton, carbon has 6, and oxygen has 8. Changing the number of protons changes the element.
- Electron Configuration: The number of protons determines the number of electrons in a neutral atom (since the number of protons equals the number of electrons in a neutral atom). The arrangement of electrons around the nucleus, particularly in the outermost shells (valence electrons), is what governs the atom's chemical properties, including how it bonds with other atoms.
- Periodic Table and Chemical Behavior: The periodic table is arranged according to the atomic number. Elements in the same group (column) have similar chemical properties because they have the same number of electrons in their outermost shell. For example, all alkali metals (first column of the periodic table) react vigorously with water, a property determined by their single electron in the outer shell.
- Isotopes: While isotopes of an element have different numbers of neutrons, they have the same number of protons. Isotopes generally have very similar chemical properties because they have the same electron configuration, even though they might have different physical properties (like mass).
So, the number of protons in an atom is fundamental in determining its chemical properties, as it defines the element, its position in the periodic table, and thus its reactivity and behavior in chemical reactions.