Chapter 3 The Atom Flashcards
What is the basic building block of all matter?
The atom
Atoms make up everything in the world, including visible and invisible substances.
How many different types of atoms are known as of the printing of this book?
118 different types
Some of these atoms are human-made and exist for a short time.
What is the Periodic Table?
A systematic way of arranging all atoms
Atoms are listed in increasing atomic number.
What do elements consist of?
Only one type of atom
Example: Oxygen is an element made up of only oxygen atoms.
What is a compound?
A substance made up of at least two different types of atoms combined
Example: Water is a compound made up of hydrogen and oxygen atoms.
True or False: Atoms change when they form compounds.
False
Atoms remain the same even when compounds are formed.
Fill in the blank: The atoms in the air you breathe in today could have been the same ones that ______.
people breathed in thousands of years ago
This illustrates the constancy of atoms over time.
What helps us understand the structure of atoms and the reactions of elements?
The organisation of the Periodic Table
The arrangement into rows and columns is crucial for understanding atomic behavior.
What is the relationship between atoms and compounds?
Atoms combine to make compounds
Compounds can break up and recombine, but the atoms themselves do not change.
What is a model in the context of science?
A representation of an object or system
What type of models are often used in science to show and explain scientific ideas?
Conceptual models
What was an example of a conceptual model mentioned in the previous chapter?
Kinetic molecular model of matter
What does the term ‘atomos’ mean in Greek?
‘Without cutting’ or ‘indivisible’
Who was the Greek scientist that proposed the idea of indivisible particles?
Democritus
What did John Dalton suggest about atoms in his atomic theory?
Matter is made up of indivisible particles called atoms
According to Dalton’s atomic theory, how do atoms of a particular element compare to atoms of other elements?
All atoms of a particular element are identical but differ from the atoms of other elements
What happens during a chemical change according to Dalton’s atomic theory?
The rearrangement of atoms in compounds, but the atoms remain intact
Fill in the blank: A model represents the current scientific understanding, and as ideas change, the _______ changes as well.
[model]
True or False: Dalton’s atomic theory states that all atoms are indivisible.
True
What did Davy, Faraday, and Berzelius discover about chemical compounds in the 1800s?
Chemical compounds are decomposed when an electrical current passes through them
This discovery indicated the electrical nature of matter.
Who proposed the name ‘electron’ for the unit of electrical charge?
Stoney
Stoney suggested that electricity consists of separate units or particles.
What did J.J. Thomson establish in 1897 regarding electrical discharge?
It is made up of very small, negatively charged particles known as electrons
These electrons were the particles predicted by Stoney.
What are protons and how do they relate to electrons?
Particles with a positive charge, equal in size to electrons but with a mass 1,836 times heavier
Protons neutralize the negative charge of electrons, making atoms overall neutral.
What was Thomson’s model of the atom?
The atom was made up of uniform positive charge with negative electrons embedded within it
This model is often likened to ‘currants in a currant bun’.