What's the Matter?
the formula for density
mass divided by volume
this term describes the energy levels of electrons and how they surround the nucleus
electron configuration
this particle carries a positive charge and is nearly identical in mass to a neutron
proton
the smallest physical unit of an element
atom
the number of significant figures in the measurement 0.004560
4
water is classified as this type of matter
compound
this state is when all electrons have their lowest possible energy level
ground state
negatively charged particles that orbit the nucleus of an atom in energy levels
electrons
these elements belong to group 18 and are not very reactive
noble gas
metric unit is used to measure the volume of a liquid and is equal to 1 cubic centimeter
milliliter (mL)
this phase is when molecules are moving the least
solid
amount of electrons that fit in the s orbital
2
this scientist proposed that electrons are arranged in distinct energy levels around the nucleus
Niels Bohr
each group on the periodic table has the same amount of these
valence electrons
the process used to convert between units, ensuring that the dimensions of the quantities are consistent
dimensional analysis
this law states that matter cannot be created or destroyed in a chemical reaction, only rearranged
law of conservation of matter
the tendency of atoms to prefer to have eight electrons in the valence shell
octet rule
maximum number of electrons that can occupy the third shell
18
this noble gas is often used to fill balloons due to is lighter-than-air properties
helium
this instrument is used to measure the volume of a liquid, typically marked with a series of graduation lines
graduated cylinder
this type of compound includes salts
ionic
specific colors emitted by each element when electrons move back to the ground state
brightline emission spectrum
this atomic model, proposed by J.J. Thomson, suggested that electrons were spread throughout a positively charged atom
plum-pudding model
this element, symbolized by Fe, is commonly found in steel and is essential for transporting oxygen in the blood
iron
When multiplying 4.56 by 0.0042, the result should be rounded to this many significant figures
2