Chemistry Flashcards
7 cards from real GCSE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Chemistry flashcards as text
Which type of bonding involves the sharing of electrons between two non-metal atoms?
Answer: Covalent bonding
Covalent bonding occurs when two non-metal atoms share pairs of electrons to achieve stable electron configurations.
What is the chemical formula for sulfuric acid?
Answer: H2SO4
Sulfuric acid has the formula H2SO4, containing two hydrogen atoms, one sulfur atom, and four oxygen atoms.
During electrolysis of brine (sodium chloride solution), what is produced at the cathode?
Answer: Hydrogen gas
At the cathode (negative electrode), hydrogen ions from water are discharged, producing hydrogen gas.
Which of the following is an example of an exothermic reaction?
Answer: Combustion of methane
Combustion of methane releases energy to the surroundings, making it an exothermic reaction.
What does the term 'mole' represent in chemistry?
Answer: 6.02 × 10²³ particles
One mole contains 6.02 × 10²³ particles (Avogadro's number), allowing chemists to count atoms and molecules by mass.
Which gas is produced when a metal carbonate reacts with a dilute acid?
Answer: Carbon dioxide
Metal carbonates react with acids to produce a salt, water, and carbon dioxide gas.
What is the oxidation state of nitrogen in NH3?
Answer: −3
In NH3, hydrogen has an oxidation state of +1, so nitrogen must be −3 to give an overall charge of zero.