Ancient Greek philosopher who suggested that atoms are solid and indivisible particles.
Who is Democritus?
100
In Ancient Greece, he suggested that atoms differ in size, shape, mass and arrangement, but also understood that all matter is made up of atoms.
Who is Democritus?
100
By bombarding this with radioactive particles, Ernest Rutherford determined that atoms were mostly empty space.
What is gold foil?
100
This is the number of major particles that make up an atom.
What is three?
100
This subatomic particle is found outside the nucleus, has insignificant mass, and has a charge of -1.
What is the electron?
200
A student of JJ Thomson, this scientist's work with particles and gold foil led him to theorize that atoms are made of mostly empty space.
Who is Ernest Rutherford?
200
This English chemist is credited with developing the first modern atomic theory. He added on to Democritus's ideas by suggesting that atoms only combine in whole number ratios.
Who is John Dalton?
200
This apparatus consists of a glass tube with a metal plate on each end; one plate is positive and one plate is negative.
What is a cathode ray tube?
200
The smallest part of an element with all the properties of the element.
What is an atom?
200
Of the three main subatomic particles, these two are found inside the nucleus.
What is the proton and neutron?
300
This scientist's "plum pudding" model, where negative particles are embedded in positive matter, arose from his work with cathode ray tubes.
Who is JJ Thomson?
300
While studying radiation of the element Beryllium, this scientist identified the neutron as a particle with the same mass as a proton, but with no charge.
Who is James Chadwick?
300
After his work with cathode ray tubes, JJ Thomson suggested that negative electrons were embedded in positive matter. This is the name of his model.
What is the plum pudding model?
300
Subatomic particle with a mass of 1 amu and a charge of 0. This particle is found in the nucleus of an atom.
What is a neutron?
300
As we move across the periodic table, these two values increase by one from one element to the next.
What is atomic number and proton number?
400
This Danish physicist was among those employed at the Cavendish Laboratory. He determined that electrons traveled in definite orbits at specific distances around the nucleus. In addition, he suggested that electrons have different levels of energy, depending on their distance from the nucleus.
Who is Niels Bohr?
400
Since he observed that the number of positive particles increases from one element to the next, this scientists designed our modern periodic table, where atoms are arranged by increasing atomic number.
Who is Henry Moseley?
400
When he placed this object near the electric current in a cathode ray tube, JJ Thomson noticed that the current bent.
What is a magnet?
400
The atomic mass of an element is equal to the sum of these.
What is the number of protons and the number of neutrons?
400
The center of an atom.
What is the nucleus?
500
The first to suggest that the periodic table be arranged in increasing atomic weight, this scientist was able to predict the properties of 8 unknown elements.
Who is Dmitri Mendeleev?
500
While working at the Cavendish lab, this scientists discovered and named the proton.
Who is Ernest Rutherford?
500
Niels Bohr's model of the atom is described as this, a vegetable that might bring someone to tears.
What is an onion?
500
The subatomic particle that is ALWAYS equal to the atomic number.