More Flashcards :)
(21 cards)
Color Change
A substance changes color unexpectedly, indicating a new substance is formed.
Example: Iron rusts, turning reddish-brown (Fe₂O₃ forms).
Gas Production
Bubbles or fumes appear, showing that a gas is being released.
Example: Baking soda reacts with vinegar to produce CO₂ bubbles.
Formation of Precipitate
A solid forms when two liquid solutions are mixed.
Example: Mixing AgNO₃ and NaCl forms a white solid (AgCl).
Temperature Change
Heat is released (exothermic) or absorbed (endothermic) during the reaction.
Example: Combustion releases heat, while photosynthesis absorbs energy.
Light or Energy Emission
The reaction produces light, sound, or electricity.
Example: Fireworks release bright flashes and sound due to chemical reactions.
Physical Property
A characteristic that can be observed or measured without changing the substance’s identity.
Example: Water boils at 100°C.
Chemical Property
A characteristic that describes how a substance interacts with other substances, resulting in a chemical change.
Example: Iron rusts when exposed to oxygen, forming Fe₂O₃.
Extensive Property
A property that depends on the amount of matter present.
Example: The mass of a gold bar is 1 kg.
Intensive Property
A property that does not depend on the amount of matter present.
Example: The density of water is 1 g/cm³.
Melting Point
The temperature at which a solid turns into a liquid.
Example: Ice melts at 0°C.
Boiling Point
The temperature at which a liquid turns into a gas.
Example: Water boils at 100°C.
Density
The mass of a substance per unit volume.
Example: The density of gold is 19.3 g/cm³.
Solubility
The ability of a substance to dissolve in another substance.
Example: Salt dissolves in water.
Flammability
The ability of a substance to burn in the presence of oxygen.
Example: Paper burns to produce ash and smoke.
Reactivity
How readily a substance reacts with other substances.
Example: Sodium reacts violently with water.
Conductivity
The ability of a substance to conduct heat or electricity.
Example: Copper is a good conductor of electricity.
Malleability
The ability of a substance to be hammered or rolled into thin sheets.
Example: Aluminum can be made into foil.
Ductility
The ability of a substance to be stretched into a wire.
Example: Gold is highly ductile and can be drawn into thin wires.
Hardness
The resistance of a material to being scratched or dented.
Example: Diamond is the hardest natural material.
Opacity
The degree to which a material blocks light.
Example: Wood is opaque, while glass is transparent.
