Unit 2 Test Flashcards
what are 3 subatomic particles and what does each one do
protons: determine identity of an element
neutrons: hold nucleus together and influence mass
electrons: determine the chemical properties of an element
how do their masses compare (according to 1)
protons/neutrons= same mass (1.67 x 10^-24) electrons= (9.11 x 10^-28)
how do electrons emit light?
when an electron moves from a high to a low energy level it results in a burst of light
how many electrons can be held in the third principal energy level
18
how many sublevels are in the 2nd principal level
2
how are the elements arranged on the modern periodic table
increasing atomic number
how many neutrons doe Rn-226 have?
140
How does an isotope differentiate from a neutral atom?
Isotopes have the same # of protons but a different # of neutrons.
(also all have different mass numbers)
Where are neutral atoms found?
periodic table
Difference between atomic mass and mass number? what do each represent?
atomic mass: weighted average mass of atoms in a naturally occurring sample of the element, reflects both the mass and relative abundance.
mass number: # of protons + neutrons
what is the stability of an isotope based on?
ratio of neutrons to protons
which type of nuclear emission is the most similar to high x-rays?
gamma
how does the atomic emission spectrum compare to the visible spectrum
visible spectrum: only small chunk (rainbow colors)
atomic emission: everything
what determines a element’s chemical properties?
electrons
how do elements configuration relate to their position on the periodic table
they show the amount of electrons (atomic number) and where they are located
whats the difference between an ion and a neutral atom
Ion has a different number of protons/electrons
describe modern atomic theory
electrons exist in a cloud
difference between physical and chemical change
chemical: change that produces matter with a different composition than the original matter
physical: some properties of a material change but the composition of the material does not change
signs of a chemical change
- forms a precipitate
- release of energy
- bubbles
- change of color
what types of substances cant be broken down by chemical processes
elements