Chapter 4 Flashcards
The nucleus of an atom is positively charged (T/F)
True
The Rutherford model of the atom states that an atom consists of a nucleus and empty space outside the nucleus (T/F)
True
The mass of the proton is two times greater than that of the neutron (T/F)
False
A neutral atom that contains 11 protons also contains 11 neutrons (T/F)
True
When electrons gain additional energy, they move farther away from the nucleus (T/F)
True
Neutrons contribute to an atom’s atomic number, but not to its mass number (T/F)
False
The chemical properties of an element depend on the number and arrangement of the protons in the atoms (T/F)
True
Isotopes have different atomic numbers, but the same mass number (T/F)
False
Aristotle stated the four elements were earth, air, water, and fire (T/F)
True
The nucleus makes up about 99.9% of the mass of the atom (T/F)
True
The smallest piece of matter was named “atom” by…
Democritus
When an electron moves to a higher energy level, it ____ energy.
Gains
The electron was discovered by…
Thomson
Rutherford’s experiment demonstrated that…
atoms have a positively charged nucleus
In Rutherford’s experiment, most positive particles fired at the gold foil…
passed right through the foil
