Science Unit 1: Chemistry Flashcards
Physical properties
texture
odour
Lustre
taste
states of matter -
hardness
Malleable -
Ductile -
melting/boiling points
crystal form -
Solubility -
Viscosity -
Density -
colour
Chemical property
flammability, toxicity, acidity, reactivity (many types), and heat of combustion.
Physical change
physical change, the substance’s appearance or form changes, but its chemical identity remains the same
Chemical change
chemical changes involve reactions where new substances are formed, often accompanied by energy changes (light, heat, electricity, sound)
Particle theory
All matter is made of tiny particles
Particles are always moving
Particles attract
Particles have tiny spaces in between them
Particles move faster when they heat up
How is matter classified?
Similarities and differences between Compounds vs elements
Elements are pure substances made of only one type of atom, while compounds are pure substances formed when two or more different elements chemically combine in a fixed ratio
Similarities and differences between Atoms vs. molecules
Atoms are single neutral particles. Molecules are neutral particles made of two or more atoms bonded together
Similarities and differences between Heterogeneous vs homogeneous
Homogeneous mixtures have uniform composition throughout (like colored water), while heterogeneous mixtures have non-uniform composition with distinct components (like salt and pepper).
Similarities and differences between Pure substances vs mixtures
Pure substances, like elements or compounds, have a definite and constant composition, while mixtures are physical combinations of two or more pure substances that retain their individual identities.
Similarities and differences between Qualitative vs quantitative
Qualitative are changes you can observe with your 5 senses, quantitative are changes that can be measured
Similarities and differences between Physical vs chemical properties
Physical properties describe a substance’s characteristics without changing its chemical identity (like color or density), while chemical properties describe how a substance behaves when it undergoes a chemical change (like flammability).
Similarities and differences between Physical vs chemical changes
Chemical changes involve reactions where new substances are formed, often accompanied by energy changes, where a physical change, the substance’s appearance or form changes, but its chemical identity remains the same
How did the hydrogen gas test work?
We mixed chemicals together to create hydrogen gas, then set the gas on fire resulting in a pop noise
How did the oxygen gas test work?
We mixed chemicals together to create oxygen, then put a glowing splint in the gas resulting in it lighting on fire from the pure oxygen.
How did the carbon dioxide gas test work?
We mixed chemicals together to create carbon dioxide gas, then put a lit splint in the gas resulting in it going out from lack of oxygen
What did Bohr contribute to the current model of the atom?
He introduced the concept of quantized energy levels and electron orbits around the nucleus.
What did Thomson contribute to the current model of the atom?
He suggested that atoms are composed of a sphere of positive charge with negatively charged electrons embedded within.
What did Dalton contribute to the current model of the atom?
He thought all matter is composed of atoms, which are indivisible and indestructible, and that atoms of a given element are identical in mass and properties.
What did Rutherford contribute to the current model of the atom?
He discovered the atomic nucleus, a small, dense, positively charged core at the center of the atom, and the concept of the atom being mostly empty space, which is a fundamental part of the current model of the atom.
What did Democritus contribute to the current model of the atom?
He introducing the concept of the atom as the fundamental, indivisible building block of matter, though his ideas were philosophical rather than based on experimentation
What is a proton?
A proton has a positive charge (+1), a mass of approximately 1 atomic mass unit (1 amu), and is located within the nucleus of an atom
What is a electron?
Electrons are negatively charged, have a very small mass (0.00054858 amu), and are located outside the nucleus of an atom, orbiting in various energy levels or electron shells
What is a neutron?
Neutrons are subatomic particles with no charge (neutral), a mass slightly greater than a proton (approximately 1 atomic mass unit), and are located within the nucleus of an atom.
