1e-Chemical formulae, equations and calculations Flashcards
Question: What is electronic configuration?
Answer: Electronic configuration refers to the arrangement of electrons in an atom’s energy levels or shells.
Question: How are electrons arranged in shells?Answer:
Electrons occupy shells around the nucleus.
The first shell can hold up to 2 electrons, the second up to 8, and the third up to 8.
Question: How do you write the electronic configuration of an element?
Answer: Write the number of electrons in each shell, separated by commas. For example:
Sodium (Na, atomic number 11): 2, 8, 1
Question: How does electronic configuration relate to the periodic table?
Answer:
The group number corresponds to the number of electrons in the outer shell.
The period number corresponds to the number of electron shells.
Question: Why are elements in the same group similar?
Answer: Elements in the same group have the same number of electrons in their outer shell, giving them similar chemical properties.
Question: How does electronic configuration affect reactivity?
Answer:
Metals (e.g., Group 1): Reactivity increases down the group because outer electrons are farther from the nucleus and easier to lose.
Non-metals (e.g., Group 7): Reactivity decreases down the group because the outer shell is farther from the nucleus, making it harder to gain electrons.
Practical: Identifying Elements Using Flame Tests
Method:
Clean a nichrome wire loop by dipping it in hydrochloric acid and heating it in a Bunsen flame.
Dip the loop in a sample of the metal compound and place it in the flame.
Practical: Identifying Elements Using Flame Tests
Results:
Lithium: Red flame
Sodium: Yellow flame
Potassium: Lilac flame
Calcium: Orange-red flame
Copper: Green flame
Practical: Identifying Elements Using Flame Tests
Conclusion:
Different elements produce characteristic flame colors due to electrons jumping to higher energy levels and releasing energy as light when they return.
