Atomic Structure Flashcards
What is Dalton’s Atomic theory?
All matter is made of tiny, indestructible particles called atoms, matter of the same element have the same mass, size, and other properties, matter of different elements have different masses, sizes and properties. Atoms of different elements can combine in simple, whole number ratios to form compounds
Why is Dalton’s theory not a law?
Because it is an explanation of observed phenomena
What is correct about Dalton’s theory?
All matter is composed of tiny, indivisible particles called atoms, atoms of the same element are identical while atoms of different elements differ.
Thomson’s plum pudding model of the atom
The electrons were embedded in a uniform sphere of positive charge. The positive matter was thought to be jelly-like. The electrons were considered somewhat mobile
Three subatomic particles and their relative mass, charge and location in the atom
Electrons are located outside the nucleus and have a negetice charge (mass is 9.11 x 10^-28)
Neutrons are located inside the nucleus and have no charge (mass is 1.67 x 10^-24)
Protons are located inside the nucleus and have a positive charge (mass is 1.67 x 10^-24)
Hg
Mercury
Au
Gold
Sn
Tin
Ag
Silver
Pb
Lead
P
Phosphorus
K
Potassium
Metalloids
Boron, silicon, tellurium, antimony, geranium, arsenic, and astatine
Nonmetals
Hydrogen, phosphorus, fluorine, sulfur, nitrogen, oxygen, carbon, bromine, helium, selenium, neon, xenon, argon, krypton, iodine, chlorine
Main group elements
Lithium, sodium, potassium, beryllium, magnesium, calcium, boron, aluminum, carbon, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, helium, neon, argon
Alkaline earth metal elements
Beryllium, magnesium, calcium, strontium, barium, radium
Alkali metals
Lithium, sodium, potassium, rubidium, cesium, francium
Noble gases
Helium, neon, argon, krypton, xenon, radon, oganesson
How are the mass number and atomic mass of an element different?
The atomic number (Z) is the number of protons in an atoms nucleus which determines its identity, while the mass number (A) is the total number of protons and neutrons in the nucleus
Atomic mass
The weighted average mass of the naturally occurring isotopes of that element, expressed as amu
Atomic mass vs. mass number
For instance: Caron, its mass number is 12 meaning 6 protons, 6 neutrons. Its atomic mass is 12.011 amu
What are ions?
An atom or molecule that has a net electrical charge, either positive or negative due to a difference in the number of protons and electrons
Cations
Atoms that lose electrons become positively charged ions
Anions
Atoms that gain electrons become negatively charged ions
