Question

What is the approximate mass of a carbon atom in atomic mass units? How about a carbon dioxide molecule?

Short answer

A carbon atom is approximately 12 amu; a carbon dioxide molecule is 44 amu.

Step-by-step solution

Understanding Atomic Mass Units

An atomic mass unit (amu) is a standard unit of mass that quantifies mass on an atomic or molecular scale. It is defined as one-twelfth of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and it is approximately equal to the mass of one nucleon (a proton or neutron), about \(1.66 \times 10^{-27}\) kilograms.

Mass of a Carbon Atom

The carbon-12 isotope is the standard where the atomic mass unit is based. A carbon atom has an atomic mass of exactly 12 amu because it is defined to be so. Therefore, the approximate mass of a carbon atom is 12 amu.

Constituents of a Carbon Dioxide Molecule

Carbon dioxide ( ext{CO}_2) consists of one carbon atom and two oxygen atoms. To find the mass of a carbon dioxide molecule, we need to add the masses of these constituents.

Mass of Oxygen Atom

An oxygen atom has an atomic mass of approximately 16 amu. Since there are two oxygen atoms in one ext{CO}_2 molecule, the total mass contributed by oxygen atoms is \(2 \times 16 = 32\) amu.

Total Mass of a Carbon Dioxide Molecule

The total mass of a ext{CO}_2 molecule is the sum of the mass of one carbon atom and two oxygen atoms. Therefore, the total mass is \(12 + 32 = 44\) amu.

Key concepts

Carbon Atom

A carbon atom is a fundamental building block in chemistry. It is primarily made up of protons, neutrons, and electrons. Positioned in the periodic table with an atomic number of 6, carbon has six protons in its nucleus. The most common isotope of carbon is carbon-12, which has six neutrons in addition to the protons.

The atomic mass unit (amu) is based on carbon-12, making it pivotal in understanding atomic masses. This isotope, by definition, has an atomic mass of 12 amu. This simplification standardizes measurements across chemistry and physics.

• Carbon is a non-metal and an essential building block of life.
• It's unique in its ability to form stable covalent bonds with other atoms, including itself.
• The versatility of carbon atoms allows for a variety of complex organic molecules.

Understanding the carbon atom's mass and structure helps us dive deeper into the complexities of chemical compounds and reactions.

Carbon Dioxide Molecule

The carbon dioxide molecule is a major component in our atmosphere, vital for processes like respiration and photosynthesis. Its chemical formula, CO extsubscript{2}, indicates it consists of one carbon atom and two oxygen atoms.

To determine the molecular weight of CO extsubscript{2}, we sum up the atomic masses of its constituent atoms:

• Carbon atom: 12 amu
• Two oxygen atoms: 2 x 16 amu = 32 amu
• Total mass of CO extsubscript{2} molecule: 44 amu

The carbon dioxide molecule is linear, with one carbon atom double-bonded to each oxygen. This configuration gives it unique properties, like its role in trapping heat as a greenhouse gas.

Understanding the structure and mass of CO extsubscript{2} aids in comprehending larger concepts like climate change and energy cycles.

Oxygen Atom

Oxygen atoms are another critical element in essential biological and chemical processes. With an atomic number of 8, oxygen has eight protons in its nucleus and generally eight neutrons, making its atomic mass approximately 16 amu.

Oxygen's role in forming molecules like water (H extsubscript{2}O) and carbon dioxide (CO extsubscript{2}) makes it indispensable in chemical reactions that support life and environmental systems.

• Oxygen is a highly reactive element and forms compounds with most other elements.
• It is crucial for cellular respiration in living organisms.
• Atmospheric oxygen is mostly found in diatomic form (O extsubscript{2}).

Knowing about the oxygen atom’s mass and reactivity helps understand its vast involvement in both organic and inorganic chemistry.

Isotopes

Isotopes are variants of elements that contain the same number of protons but different numbers of neutrons, leading to differences in mass. Carbon and oxygen both have isotopes, though carbon-12 and oxygen-16 are the most common and stable.

• Carbon-14 is an isotope used in radiocarbon dating to determine the age of archaeological finds.
• Oxygen has several isotopes, such as oxygen-18, which is used in paleoclimatology to study ancient climates.
• The mass differences among isotopes affect physical and chemical properties slightly, often exploited in scientific research.

Understanding isotopes is crucial in fields like geology, archaeology, and environmental science because they can reveal historical, climatic, or geological information. By knowing isotopes, we can further comprehend the variances and consistencies between atomic structures and their historical significance.