The Atom
What charge do protons have?
Positive charge.
Who proposed the model that described electrons orbiting the nucleus?
Rutherford
What is a mixture?
A combination of two or more substances that are not chemically bonded.
What does purity refer to in chemistry?
The amount of a specific component in a mixture.
What is the charge of neutrons?
No charge
What did Thomson contribute to atomic theory?
The discovery of the electron
Distilled water is an example of
pure substance
How gold purity is measured?
Carats
What are the particles with negative charge?
Electrons
What did Chadwick discover?
The neutron
What are the two main types of mixtures?
Homogeneous and heterogeneous mixtures.
How can you test the purity of a substance?
By comparing its properties to those of a known pure substance.
What holds atoms together?
Electrostatic attraction between positive and negative charges.
Describe the Rutherford model of the atom
The atom has a small, dense nucleus with a positive charge, with electrons orbiting around it.
How can you tell if a substance is a mixture?
If it can be separated into its individual components by physical means.
How would you define a substance with 100% purity?
A substance that contains only one type of molecule
Describe the relationship between protons, electrons, and the overall charge of an atom.
An atom is neutral because the number of protons is equal to the number of electrons.
Compare and contrast the Thomson and Rutherford models of the atom.
Thomson's model solid sphere with a positive charge and electrons embedded, while Rutherford's model proposed a dense nucleus with electrons orbiting around it.
What is the difference between a homogeneous mixture and a heterogeneous mixture?
A homogeneous mixture has a uniform composition, while a heterogeneous mixture has distinct, separate components.
Explain why a chemist might want to know the purity of a sample.
To ensure accuracy in experiments of the substance being used.