hat is the smallest unit of matter?
atom
What part of the atom has a positive charge?
proton
Who was the first person to suggest that everything is made of atoms?
Democritus
rue or False: Atoms are mostly empty space
true
What is the lightest element on the periodic table?
hydrogen
True or False: Atoms can be seen with the naked eye
false
What is the negatively charged part of an atom?
electron
Who discovered the electron?
J.J. Thomson
What do you call atoms of the same element with different numbers of neutrons?
isotopes
What is the chemical symbol for gold?
Au
Atoms combine to form what larger structures?
molecules
What part of the atom has no charge?
neutron
Which scientist developed the nuclear model of the atom?
Ernest Rutherford
What part of the atom determines which element it is?
protons
How many elements are in the periodic table?
118
What is the center of an atom called?
nucleus
Where are electrons found in an atom?
cloud
Who created the first periodic table of elements?
Dmitri Mendeleev
What is the heaviest naturally occurring element?
uranium
What is the only metal that is liquid at room temperature?
mercury
What is the name for a group of atoms bonded together?
molecule
What part of the atom determines the atom's mass?
protons and neutrons
Who developed the planetary model of the atom?
Niels Bohr
What is the name of the force that holds the nucleus together?
strong nuclear force
Which element has the highest atomic number on the periodic table as of 2024?
Oganesson (Og)