A
What do you called the positively charged particle?
PROTON
Who first proposed that matter is made up of tiny, indivisible particles called “atomos”?
DEMOCRITUS
What is the central part of an atom that contains protons and neutrons?
NUCLEUS
Which subatomic particle has a negative charge?
Who discovered the electron through the cathode ray experiment?
JOSEPH JOHN THOMSON/J.J THOMSON/THOMSON
Isotopes of an element differ in the number of __________.
NEUTRON
Which isotope is commonly used in carbon dating?
C-14
What experiment led Ernest Rutherford to discover the nucleus of the atom?
GOLD-FOIL EXPERIMENT
If an atom has 6 protons, 6 neutrons, and 6 electrons, what is its atomic mass?
12 amu
Write the nuclear notation of a carbon isotope with 6 protons and 8 neutrons.
¹⁴₆C
Which part of an atom is responsible for its chemical behavior?
Electrons (in the outermost shell/valence electrons)
Why are isotopes of the same element considered chemically similar?
because they have the same number of protons and electrons, which determine chemical behavior.
Give the correct arrangement of scientists based on their contribution to atoms.
DEMOCRITUS-DALTON-THOMSON-RUTHERFORD-BOHR-SCHRODINGER
Define atomic mass unit (amu)
A unit of mass used to express atomic and molecular weights.
1/2 the mass of a Carbon-12 atom.
Why are isotopes with unstable nuclei considered radioactive?
because their nuclei are unstable and broken down, resulting to a releasing radiation.
Give one practical use of radioactive isotopes in the medical field.
Treatment of cancer (cobalt-60)
Medical imaging (technetium-99m)
Thyroid treatment (iodine-131).
Who is known as the “Father of Modern Atomic Theory”?
JOHN DALTON
Which subatomic particle has no charge?
Who proposed the model of the atom that looks like a miniature solar system?
NIELS BOHR
What is the smallest particle of an element that retains its properties?
ATOM/ATOMS
What do you call atoms of the same element with different mass numbers?
ISOTOPES
How do we calculate the number of neutrons of the given element?
Number of Neutrons=Mass Number (A)−Atomic Number (Z)
How do we get the mass number if the given are protons, neutrons & electrons?
By adding the number protons and neutrons.
The atomic number of an element is equal to the number of protons. TRUE OR FALSE.
TRUE
The Bohr model describes electrons orbiting the nucleus like planets around the sun. TRUE OR FALSE
TRUE