Atoms, Elements, and Compounds Flashcards
(45 cards)
What is an element?
a substance that can’t be broken down into anything simpler using chemical reactions. composed of only one type of atom.
What is a relative mass?
measuring the mass of atoms/ molecules by comparing them to the standard of 1/12th of a carbon-12 atom.
What is an atom?
the smallest possible component of a matter.
What is the atomic number?
the number of protons in the nucleus of an atom (proton number)
What are atoms composed of?
- electrons
- protons
- neutrons
What is a mixture?
two or more chemical substances found together but not chemically bonded
What are compounds?
a substance made of two or more elements chemically bonded together.
What are isotopes?
atoms with the same proton number but different nucleon numbers.
What is the periodic table?
a table showing all the elements in the universe.
What is a period in the Periodic Table?
the horizontal rows of the Periodic Table which tell you how many electron shells an element has.
What is the mass number?
the number of protons and neutrons in the nucleus of an atom.
no. protons + no. neutrons = mass number
mass no. - proton no. = number of neutrons
What is electronic configuration?
the distribution of electrons of an atom/ molecule in electron shells.
What are noble gases?
Elements from Group VIII (8)
that are unreactive as their outer shells are full of electrons.
What are the properties of Group 8 noble gases?
- very stable
- full outer shell
- unreactive (inert)
- colorless
- odorless
- tasteless
- low MP / BP
What are ions?
an electrically charged particle formed when atoms gain / lose electrons.
Which groups will always lose electrons/have positive charge?
- Group I (1)
- Group II (2)
- Group III (3)
exp: Sodium becomes Na+
Which group will always gain electrons/have negative charge?
- Group V (5)
- Group VI (6)
- Group VII (7)
exp: Oxygen becomes O 2-
What is the nuclear notation?
a method for displaying the key data of an element and its isotopes.
The symbol for the element is preceded by the proton number (bottom) and nucleon number (top).
exp:
35
Cl
17
What is the formula to find average atomic mass?
(sum of (atomic mass x % abundance) for each isotope) / 100
pr
(sum of (atomic mass x relative abundance) for each isotope) / sum of relative abundance
exp: 40% 12C, 32% 13C and rest is 14C
Abundance = 100 - (40+32) = 28% of 14C
Av. Mass = ((12X40) + (13X32) + (14X28)) / 100
Average Relative Atomic Mass = 12.9
What are cations?
positively charged ions
What are anions?
negatively charged ions
What is ionic bonding?
chemical bonding that occurs when metals transfer electrons to non metals to form ions.
What is an ion?
an electrically charged particle formed when an atom loses / gains electrons.
What are electrostatic forces?
the powerful attractive forces between oppositely charged particles.
