Atomic Theory
What are the different parts on an atom? Where are they located and what is the charge of each? (hint: 3 particles and the center of the atom)
Proton- positive charge located in the nucleus
Electron- negative charge surrounding the nucleus
Neutron- no charge located in the nucleus with the protons
Nucleus- center of the atom that holds the protons and neutrons
What is the periodic table and what information is contained in each cell of the elements in the Periodic Table?
The Periodic Table is an arrangement of chemical elements based on their atomic number, electron configuration, and recurring chemical properties. It provides a systematic way of organizing and displaying the elements.
Each cell shows: atomic number, atomic mass, symbol, and name
Explain what Bohr's Model is. What does it show? On a piece of paper, draw what Boron would look like in Bohr's Model.
it shows the arrangement of of electrons. Boron will have p=5 n=6 e=5 and 2 electrons on first shell, 3 valance electrons
In most bonding, how many valence electrons makes an element stable? What is the max amount of electrons that can go on the 1st shell of an atom?
8 and 2
What are the properties of an acid? What pH levels do they range from?
Reactions with metals- corrosive, they disappear in solution
reactions with carbonates- turns to gas. limestones react with acids
sour taste
reactions with indicators- turns blue litmus paper red and pH level is 0-6
What was the last discovered particle of an atom? Why was it so hard to find it? (two reasons)
neutrons do not have a charge so it was hard to find them and they are held tightly together with the protons in the nucleus, so they could not observe the behavior of them independently
What are the rows and columns called in the periodic table?
groups and periods
How do you find the number of protons? How do you calculate the Mass number? How do you know how many electrons are in an atom?
protons= atomic number
mass number = protons + neutrons
neutrons = mass number - protons
electrons = protons
What are the 2 types of bonds and list 2 characteristics of each.
ionic bonding- transfers valence electrons, and forms between metals and nonmetals.
Covalent bonding- shares valence electrons and forms between nonmetals.
What are the properties of a base? What pH levels do they range from?
reactions with indicators- turns red litmus paper blue and pH level 8-14
bitter taste
slippery feel
What is the Atomic Theory? Why is it a Theory?
The Atomic Theory is a scientific model that explains the nature of matter by proposing that all matter is composed of tiny, indivisible particles called atoms. The theory suggests that atoms combine in various ways to form molecules and compounds, and chemical reactions involve the rearrangement of these atoms.
The Atomic Theory has evolved over time with contributions from different scientists. John Dalton is often credited with formulating the modern Atomic Theory in the early 19th century. The key principles of the theory include:
Atoms are indivisible: Atoms are the smallest units of matter and cannot be divided into smaller particles.
Conservation of mass: In a chemical reaction, the total mass of the reactants is equal to the total mass of the products.
Definite proportions: Compounds are formed by the combination of atoms in simple, whole-number ratios.
Multiple proportions: When elements combine to form more than one compound, they do so in simple, whole-number ratios.
The Atomic Theory is considered a scientific theory because it has been supported by extensive experimental evidence and has successfully explained a wide range of observations related to the behavior of matter.
Why are elements organized in a periodic table? What different properties did Dmiti Mendeleev organize the periodic table with?
Properties of the elements repeat in a cycle or repeating pattern. He organized the elements based on melting point, density, color and atomic mass.
Explain what the Lewis Dot Diagram is. What does it show? On a piece of paper, draw what Sulfur would look like in a Dot Diagram.
Lewis Dot structure shows the valance electrons. Sulfur would be S with 6 valance electrons
What elements are most likely to bond with an element that has 2 valence electrons?
any element in group 16
What 2 formulas will complete the neutralization of Lithium Fluoride (LiF). Hint: Lithium is the base, Fluoride is the acid. Think about which has a higher concentration of O+ and OH-......
Acid: HF
Base: LiOH
Why was it so difficult to develop the Atomic Theory?
because Atoms are to small and we did not have the most efficient technology back then. As time went on, our microscopes became more advanced.
What group numbers contain the metals, nonmetals and transition metals? AND how does the table organize most reactive to least reactive? Why is that? (hint: Valance electrons)
metals: 1 and 2
transiition metals: 3-12
nonmetals: metalloids to gases (13-18)
left to right, reactive to least reactive because there are less amount of valance electrons on the left side and more on the right side. The more valance electrons, the least reactive they are.
What is the pattern of the valence electrons in the periodic table?
group 1= 1
group 2= 2
group 13= 3
group 14= 4
group 15= 5
group 16= 6
group 17= 7
group 18= 8
What elements are most likely to bond with Sodium?
Any element in group 17.
What happens when acid reacts with metals? What property of acids would cause acid rain to damage a metal statue? How can you prevent something from wearing away the statue?
limestone, corrosiveness and you can cover the statue somehow.
How has the Atomic Theory Changed over the years? Think of the different scientist throughout the years.
John Dalton (1766–1844):
Thomson (1856–1940):
Rutherford (1871–1937):
Bohr (1885–1962):
determined that electrons do not move in specific orbits like planets do, instead they move rapidly within a cloud region around the nucleus.
What can you tell us about the different groups in the periodic table? Hint: why are they organized in that way.
Part two: Out of metals, nonmetals, and metalloids which...
are better conductors?
are malleable?
ductile?
poor conductor?
semiconductor?
reactive/unreactive?
better conductors: metals
malleable: metals
ductile: metals
poor conductor: nonmetals
semiconductor: metalloids
reactive: metals
unreactive: nonmetals
Find the question marks.
Isotope- Uranium-238 Thorium- 234
Protons- 92 ?
Neutrons- ? 144
Electrons- 92 ?
Find the question marks.
Isotope- Uranium-238 Thorium- 234
Protons- 92 90
Neutrons- 146 144
Electrons- 92 90
What are the metalloids in the Periodic Table?
Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Astatine.
What is the difference between pH strips and litmus paper?
litmus paper is either red or blue and they only change to red or blue.
pH strips give you the pH level of a substance using a pH scale