Q: chem: All [...](substances) are made of atoms.
A: elements

Q: chem: All elements are made of [...].
A: atoms

Q: chem: Each element contains [...](number) kind(s) of atom.
A: one

Q: chem: What makes one element different from another?
A: Their atoms.

Q: chem: Every atom can be divided into 3 different components:
Q: - [...],
Q: - neutrons,
Q: - electrons.
A: protons

Q: chem: Every atom can be divided into 3 different components:
Q: - protons,
Q: - [...],
Q: - electrons.
A: neutrons

Q: chem: Every atom can be divided into 3 different components:
Q: - protons,
Q: - neutrons,
Q: - [...].
A: electrons

Q: chem: What is the center of an atom?
A: nucleus

Q: chem: The nucleus is made of:
Q: - [...],
Q: - neutrons.
A: protons

Q: chem: The nucleus is made of:
Q: - protons,
Q: - [...].
A: neutrons

Q: chem: What kind of electrical charge does proton have?
A: positive

Q: chem: T/F: Protons have positive electrical charge.
A: True.

Q: chem: T/F: Protons have negative electrical charge.
A: False.

Q: chem: T/F: Protons have no electrical charge.
A: False.

Q: chem: What kind of electrical charge does neutron have?
A: none

Q: chem: What does it mean that neutrons are neutral?
A: They have no electrical charge.

Q: chem: T/F: Neutrons have positive electrical charge.
A: False.

Q: chem: T/F: Neutrons have negative electrical charge.
A: False.

Q: chem: T/F: Neutrons have no electrical charge.
A: True.

Q: chem: What kind of electrical charge does electron have?
A: negative

Q: chem: T/F: Electrons have positive electrical charge.
A: False.

Q: chem: T/F: Electrons have negative electrical charge.
A: True.

Q: chem: T/F: Electrons have no electrical charge.
A: False.

Q: chem: What elementary particles orbit the nucleus?
A: Electrons.

Q: chem: Around what elementary particle do electrons move?
A: Nucleus.

Q: chem: The number of what elementary particles must equal the number of protons in order to make atoms electrically neutral?
A: Electrons.

Q: chem: The number of what elementary particles must equal the number of electrons in order to make atoms electrically neutral?
A: Protons.

Q: chem: What kind of electrical charge does atom have if the number of electrons is equal to the number of protons?
A: None (i.e. it is neutral)

Q: chem: Atoms are electrically neutral if the number of electrons [is/is not] equal to the number of protons.
A: is

Q: chem: What is the defining feature of an atom?
A: The number of protons (in an atom).

Q: chem: [...] in an atom is called its atomic number.
A: The number of protons

Q: chem: How is the number of protons in an atom called?
A: Atomic number.

Q: chem: What is the atomic number of oxygene if its atom has 8 protons?
A: 8

Q: chem: Where are all the elements in the universe arranged according to their atomic number?
A: In the periodic table (of elements).

Q: chem: According to which number are all the elements in the universe arranged in the periodic table?
A: Atomic number.

Q: chem: atomic number + the number of neutrons (in the nucleus of an atom) = [...]
A: mass of the atom

Q: chem: [...] + the number of neutrons (in the nucleus of an atom) = mass of the atom
A: atomic number

Q: chem: atomic number + [...] (in the nucleus of an atom) = mass of the atom
A: the number of neutrons

Q: chem: What is the mass number for Helium if it has 2 protons and 2 neutrons?
A: 4

Q: chem: How are atoms with the same number of protons but different numbers of neutrons called?
A: Isotopes.

Q: chem: Atoms with the same number of [...](elementary particles) but different numbers of neutrons are called isotopes.
A: protons

Q: chem: Atoms with the same number of protons but different numbers of [...](elementary particles) are called isotopes.
A: neutrons

Q: chem: Atoms with [the same/different] number of protons and different numbers of neutrons are called isotopes.
A: the same

Q: chem: Atoms with the same number of protons and [the same/different] numbers of neutrons are called isotopes.
A: different
