Science test Flashcards
Circuits and acids/alkalis (36 cards)
What is a chemical reaction?
Atoms are rearranged to make new substances.
What is a physical change?
Only particle arrangement, movement, and energy change — no new substances.
What does toxic mean?
Poisonous, extremely hazardous to health.
What does flammable mean?
Can catch fire easily.
What does corrosive mean?
Can dissolve or burn materials, including skin.
What does health hazard mean?
Harmful to health but not as deadly as toxic.
What does caution (irritant) mean?
Mildly harmful or irritating.
What is concentration?
Amount of solid dissolved per unit volume (g/cm³ or g/dm³).
Difference between concentrated and dilute?
Concentrated = many particles; dilute = few particles.
What is an acid?
Releases H⁺ ions in water.
What is an alkali?
Releases OH⁻ ions in water.
What is a base?
Reacts with acids, can be insoluble.
What is neutralisation?
H⁺ + OH⁻ → H₂O.
What is a salt?
Made in a neutralisation reaction between metal and non-metal.
What is a strong acid?
Releases lots of H⁺ ions.
What is a weak acid?
Releases few H⁺ ions.
What does the pH scale show?
How acidic or alkaline a solution is (low pH = strong acid).
What does universal indicator do?
Shows pH with color changes.
What does litmus paper do?
Turns red in acid, blue in alkali.
What is current?
Flow of charge per second, measured in amps (A).
What is potential difference (voltage)?
Energy transferred per charge, measured in volts (V).
What is resistance?
How hard it is for current to flow, measured in ohms (Ω).
Formula for resistance?
Resistance = Voltage ÷ Current.
What is a series circuit?
One continuous path for current.
