Vocabulary
Pure substance
A material that is made of the same tiny particles
Explain Dalton's theory of the atom
all things are made up of tiny particles called atoms, atoms cannot be created destroyed or divided into smaller pieces, atoms have identical sizes and mass in the same pure substance each substance is different, compounds are created when atoms of different elements link together
Chemical Change
causes one or more new substances
What is physical property?
something you can observe or measure
Explain the law of definite composition
compounds are pure substances that contain two or more elements combined together in a definite proportion
Alchemist
hands on investigator of matter, part pharmacist, part mystic, practiced in Europe and Middle East
Explain Thomson's theory of the atom?
Plum pudding or raisin bun model, he pictured the negatively charged electrons stuck in the positively charged mass like a raisin bun
is when a substance changes in form but not in chemical composition.
what is chemical property?
anything that explains how it will react with another substance
Explain the law of conservation of mass
In a chemical change the total mass of the new substance is always the same amount as the original substance.
Electrolysis
The process of decomposing chemical compounds by running electricity through them
Explain Rutherford's theory of the atom?
he hypothesized that all mass of the atom was in the center known as the atomic nucleus. The rest of the atom was empty and full of smaller electrons, he also gave positively charged particles the title protons.
List the clues that help to determine if it is a chemical change
Changes are difficult to reverse, heat is released or absorbed, starting material is used up, gas bubbles formed in liquid, participate forms in liquid, change in color, material with new properties is formed
In what two groups can physical property be split in?
Quantitive and Qualitative physical property
What did Antoine Lavoisier do for the study of chemistry?
defined elements as pure substances that cannot be decomposed into a similar substance by means of chemical change, found 23 pure substances
Homogeneous
when particles are evenly distributed and cannot be seen in the mixture
Explain Bohr's theory of the atom
pictured the atom like a mini solar system with electrons rotating around an atomic nucleus, he refined this model by saying the electrons move on fixed pathways similar to planets in the solar system
Give an example of physical change
ice -> water
What is Quantitive physical property?
Something that can be measured. Ex. viscosity
What did Robert Boyle discover in the early years of chemistry
He recognized that elements could be combined to form compounds laying the ground work for the future of chemistry.
Heterogeneous
when particles are not evenly distributed and can be seen in the mixture
Explain Shrodinger's theory of the atom
found that electrons have certain energy levels and acted as waves, he then provided a mathematical formula to determine where an electron was in relation tot the nucleus. This is known as the election cloud model.
Give an example of chemical change
burning wood
What is Qualitative physical property?
something that can be described. Ex. Color
List the 5 points on the Particle Model of Matter
All things are made up of tiny particles, Particles are always in motion, Particles are attracted to each other, Each pure substance has unique particles different from other pure substances, Particles at high temp move faster than particles at low temp