Atoms
The number of protons in the nucleus.
What is the atomic number?
This man first tested rays that traveled through a tube with electricity flowing through it.
Who was William Crookes?
A period of the table runs in this direction.
What is horizontal?
(across)
This type of matter can vary in composition.
What is a mixture?
(must not a subcategory)
What J.J. Thomson used to show that the ray in the cathode ray tube was a negatively charged particle.
What is a magnet?
The charge of an electron.
What is negative?
The people from whom Dalton got many of his ideas about atoms.
Who were Ancient Greeks?
(Greek philosophers)
A column on the table is called this.
What is a group?
A wire of solid copper is in this category.
What is an element?
True or False:
Air is a compound.
False. It is a homogeneous mixture.
The average total of protons and neutrons in an atom of an element.
What is the atomic mass?
(atomic mass unit)
This scientist revised Dalton's model to include negatively charged particles spread evenly throughout a positive sphere.
Who was J.J. Thomson?
The elements on the periodic table are in numerical order of this.
What is the atomic number?
(or # of protons in the nucleus)
This type of matter has a chemical formula.
What is a compound?
A material's ability to be drawn into wires without breaking.
What is ductility?
A balanced atom with 12 electrons has this atomic number.
What is 12?
This man found that Thomson's model was inaccurate.
Who was Ernest Rutherford?
The bottom number on an element's tile indicates this.
What is the atomic mass unit?
(average atomic mass)
A peanut butter sandwich is this type of matter.
What is a heterogenous mixture?
An atom that has lost an electron has this charge.
What is a positive charge?
These are atoms of the same element with different numbers of neutrons.
What are isotopes?
The name of the atomic model accepted by scientists today.
What is the electron cloud model?
True or False:
The periodic table we use today was created by French chemists Marie and Antoine Lavoisier.
False.
They made an early version of the periodic table.
Another name for a homogeneous mixture.
What is a solution?
This scientist calculated where an electron is most likely found in an atom.
Who is Niels Bohr?