The weighted average mass of the atoms in a naturally occurring sample of an element is the average atomic mass, also known as atomic weight.
What is atomic mass?
The average mass of an element's atoms expressed in atomic mass units is known as its atomic mass (amu, also known as daltons, D).
The mass of each isotope is multiplied by its abundance to produce the atomic mass, which is a weighted average of all the isotopes of that element.
Any element has a variety of isotopes, thus to take into consideration the fact that each isotope has a different mass, a weighted average mass is used.
A weighted average takes into account the potential that an element's average mass, as calculated from a random sample, will most likely coincide with the average mass of its more common isotopes.
The weighted average masswill therefore be closest to that of the more prevalent isotopes.
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Answer:
Explanation:
Substances with giant covalent structures are solids with high melting and boiling points due to the nature of the covalent bonds and the three-dimensional network they form within the crystal lattice. This structure is also often referred to as a network covalent structure. Let's break down the key reasons why these substances have such properties:
1. **Strong Covalent Bonds**: In giant covalent structures, each atom forms strong covalent bonds with neighboring atoms. Covalent bonds involve the sharing of electrons between atoms. This sharing results in the formation of very strong and directional bonds, which require a significant amount of energy to break.
2. **Three-Dimensional Network**: In these substances, the covalent bonds extend in a three-dimensional network throughout the entire structure. This means that every atom is bonded to several neighboring atoms in all three spatial dimensions. This extensive network of covalent bonds creates a robust and interconnected structure.
3. **Lack of Weak Intermolecular Forces**: Unlike some other types of solids (e.g., molecular solids or ionic solids), giant covalent structures lack weak intermolecular forces, such as Van der Waals forces. In molecular solids, weak intermolecular forces are responsible for their relatively low melting and boiling points. In giant covalent structures, the primary forces holding the atoms together are the covalent bonds themselves, which are much stronger.
4. **High Bond Energy**: The covalent bonds in giant covalent structures have high bond energies, meaning that a substantial amount of energy is required to break these bonds. When a solid is heated, the energy provided must be sufficient to overcome the covalent bonds' strength, leading to the high melting and boiling points.
5. **Rigidity and Structural Integrity**: The three-dimensional covalent network imparts rigidity and structural integrity to the substance. This network resists deformation and allows the substance to maintain its solid form at high temperatures, as the covalent bonds continuously hold the structure together.
Examples of substances with giant covalent structures include diamond (composed of carbon atoms), graphite (also composed of carbon atoms but arranged differently), and various forms of silica (e.g., quartz and silicon dioxide). Diamond, in particular, is known for its exceptional hardness, high melting point, and remarkable optical properties, all of which are attributed to its giant covalent structure.
In summary, giant covalent structures have high melting and boiling points because of the strong covalent bonds, the three-dimensional network of bonds, and the absence of weak intermolecular forces. These factors combine to create a solid with exceptional stability and resistance to temperature-induced phase changes.
Substances with simple molecular structures are usually gases, liquids, or solids with low melting points due to the intermolecular forces between their molecules. The chemical identities of the molecules determine the types and strengths of these attractions, influencing the physical state of the substance.
Substances with simple molecular structures tend to be gases, liquids, or solids with low melting and boiling points because of the nature of intermolecular forces at play. Intermolecular forces are the attractions between molecules, which determine many of the physical properties of a substance. For instance, small, symmetrical molecules, such as H2, N2, O2, and F2, have weak intermolecular attractive forces and form molecular solids with very low melting points (below -200 °C).
In a liquid, intermolecular attractive forces hold the molecules together, though they still have sufficient kinetic energy to move relative to each other. In gases, the molecules have large separations compared to their sizes due to which the forces between them can be ignored, except during collisions.
Therefore, the chemical identities of the molecules in a substance determine the types and strengths of intermolecular attractions possible; this subsequently influences whether the substance is a gas, liquid, or solid, and its melting and boiling points.
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parasitism
B.
amensalism
C.
commensalism
D.
symbiosis
Answer: C: commensalism please give me hearts and stars because the answer is right!!
Explanation:
The relationship between the clown fish and the deadly sea anemone can be classified as commensalism. Though the sea anemone’s tentacles are covered with thousands of nematocysts (tiny, venomous harpoons), the clown fish is protected by a thick coat of mucus and is not harmed by the anemone’s venom. The clown fish is therefore protected from predators and is also able to get leftover food from the anemone's meals. Since the clown fish ultimately benefits from this arrangement and the sea anemone neither benefits nor suffers because of the clown fish, the relationship is commensalistic.
The clown fish and the sea anemone exhibit a mutualistic relationship, where both organisms benefit. However, among the options provided in the question, the most accurate is 'symbiosis', which broadly denotes a close, long-term interaction between different biological species.
The symbiotic relationship between the clown fish and the sea anemone is referred to as mutualism. This term, which is missing from the options, indicates a relationship in which both organisms benefit. The clown fish is protected from predators and has access to food remnants, whereas the sea anemone gets cleaned by the clown fish, which removes parasites and debris. Among the options provided, the closest would be symbiosis (option D), as it describes a close, long-term interaction between different biological species, which can include mutualism, commensalism, and parasitism.
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(2) CH2O (4) C12H24O12
B. Atomic nuclei possess shells similar to the electron shells of atoms.
C. Some atoms contained more protons than electrons.