Understanding Atomic and Molecular Mass
The concept of masa atomowa atomicmass is fundamental in chemistry. It represents the mass of an atom relative to the carbon-12 isotope. The jednostka masy atomowej atomicmassunit,u is used as the standard unit for measuring atomic and molecular masses.
Definition: Masa atomowa is the mass of an atom expressed in atomic mass units u.
Examples of atomic masses are provided:
- Sodium Na: 22.990 u
- Oxygen O: 15.999 u
Example: The masa atomowa of sodium Na is 22.990 u, while that of oxygen O is 15.999 u.
The concept of masa cząsteczkowa molecularmass is also introduced. It is defined as the sum of the atomic masses of all atoms in a molecule.
Definition: Masa cząsteczkowa is the total mass of a molecule, calculated by summing the atomic masses of its constituent atoms.
An example calculation for the molecular mass of hydrogen sulfide H2S is provided:
- 2 hydrogen atoms H: 2 × 1 u = 2 u
- 1 sulfur atom S: 32 u
- Total molecular mass of H₂S: 2 u + 32 u = 34 u
Example: Jak obliczyć masę cząsteczkową of H₂S: Add the masses of 2 hydrogen atoms 2×1u and 1 sulfur atom 32u to get 34 u.
The document also mentions helium He with an atomic mass of approximately 4 u.
Highlight: Understanding how to calculate masa cząsteczkowa is crucial for solving chemistry problems and understanding chemical reactions.
This information provides a solid foundation for students learning about atomic and molecular masses, which is essential for further studies in chemistry and related fields.
