Matter, Elements, and Compounds Flashcards
7 cards from real BECE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Matter, Elements, and Compounds flashcards as text
What does the subscript '2' in H₂O indicate?
Answer: There are 2 hydrogen atoms
The subscript 2 after H means there are 2 hydrogen atoms in each molecule of water.
How many atoms are present in one molecule of sulfuric acid (H₂SO₄)?
Answer: 7
H₂SO₄ contains 2 hydrogen + 1 sulfur + 4 oxygen = 7 atoms total per molecule.
An ionic bond typically forms between:
Answer: A metal and a nonmetal
Ionic bonds form when a metal transfers electrons to a nonmetal, creating oppositely charged ions that attract each other.
The Law of Conservation of Mass states that:
Answer: The total mass of reactants equals the total mass of products
In a chemical reaction, matter is neither created nor destroyed — total mass remains constant.
Which element is most abundant in Earth's crust by mass?
Answer: Oxygen
Oxygen makes up approximately 46% of Earth's crust by mass, mostly found in minerals and oxide compounds.
The chemical symbol Cu for copper comes from:
Answer: The Latin word 'Cuprum'
Cu comes from the Latin 'Cuprum,' named after the island of Cyprus, a major ancient source of copper.
Which statement correctly describes a pure substance?
Answer: It has a definite and uniform composition
Pure substances (elements and compounds) have a fixed, uniform composition, unlike mixtures.