Update | 2024/2025 | Already Passed
What is the difference between a chemical change and a physical change in terms of matter?
✔✔ A chemical change results in the formation of new substances with different properties,
while a physical change involves a change in the state or appearance of matter without altering
its chemical composition.
How do you determine the number of neutrons in an atom given its atomic number and mass
number?
✔✔ The number of neutrons can be determined by subtracting the atomic number from the mass
number.
What is the significance of the atomic number of an element?
✔✔ The atomic number represents the number of protons in the nucleus of an atom, which also
determines the element's identity and its position in the periodic table.
How can you distinguish between an ionic compound and a covalent compound based on their
properties?
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, ✔✔ Ionic compounds typically have high melting points, conduct electricity when dissolved in
water, and consist of metals and nonmetals, while covalent compounds usually have lower
melting points and do not conduct electricity, consisting of nonmetals.
What is the principle behind the law of conservation of mass in chemical reactions?
✔✔ The law of conservation of mass states that mass is neither created nor destroyed in a
chemical reaction; the total mass of reactants equals the total mass of products.
How is the concept of atomic orbitals used to describe the arrangement of electrons in an atom?
✔✔ Atomic orbitals describe regions in an atom where electrons are likely to be found, and they
help define the distribution of electrons in different energy levels and sublevels.
What information does the molecular formula of a compound provide about its composition?
✔✔ The molecular formula provides the exact number of each type of atom in a molecule,
indicating the composition and number of each element present.
How does the principle of electronegativity help predict the type of bond formed between two
atoms?
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