February 07, 2018
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Review topic 2 Underlying structures of matter with answers.notebook 1 February 07, 2018 Sep 711:05 PM Review Topic 2: Underlying Structures of Matter Chapter 4: Atomic Structure (1,2,3) Chapter 5: Electrons in Atoms (1) VOCABULARY Atom the smallest particle of an element that keeps its identity in a chemical reaction Nucleus tiny central core of an atom that is made up of protons and neutrons Atomic number the number of protons in the nucleus of an atom of that element Sep 711:15 PM Mass Number the total number of protons and neutrons in an atom Isotope atoms that have the same number of protons but different number of neutrons Atomic Mass Unit (amu) unit used to describe the mass of an atom Orbits circular paths that electrons travel around the nucleus Energy levels the fixed energies an electron can have Quantum the amount of energy required to move an electron from one energy level to another energy level. Sep 711:24 PM Scientists Democritus believed that atoms were indivisible and indestructible J.J. Thomson discovered the electron Eugen Goldstein discovered the proton Sep 711:31 PM James Chadwick discovered the neutron Ernest Rutherford discovered the nucleus and concluded that it was positive and that electrons travelled around it Sep 711:34 PM Hantaro Nagaoka suggested that the atom has a central nucleus. Electrons move in orbits like the rings around Saturn Niels Bohr believed that electrons move in a circular orbit at fixed distances from the nucleus Sep 711:40 PM Louis de Broglie proposed that moving particles like electrons have some properties of waves. Erwin Schrodinger develops mathematical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model.
Transcript of February 07, 2018
Review topic 2 Underlying structures of matter with answers.notebook
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February 07, 2018
Sep 711:05 PM
Review Topic 2: Underlying Structures of Matter
Chapter 4: Atomic Structure (1,2,3)
Chapter 5: Electrons in Atoms (1)
VOCABULARYAtom the smallest particle of an element that keeps its
identity in a chemical reaction
Nucleus tiny central core of an atom that is made up of protons and neutrons
Atomic number the number of protons in the nucleus of an atom of that element
Sep 711:15 PM
Mass Number the total number of protons and neutrons in an atom
Isotope atoms that have the same number of protons but different number of neutrons
Atomic Mass Unit (amu) unit used to describe the mass of an atom
Orbits circular paths that electrons travel around the nucleus
Energy levels the fixed energies an electron can have
Quantum the amount of energy required to move an electron from one energy level to another energy level.
Sep 711:24 PM
ScientistsDemocritus believed that atoms were indivisible and
indestructible
J.J. Thomson discovered the electron
Eugen Goldstein discovered the proton
Sep 711:31 PM
James Chadwick discovered the neutron
Ernest Rutherford discovered the nucleus and concluded that it was positive and that electrons travelled around it
Sep 711:34 PM
Hantaro Nagaoka suggested that the atom has a central nucleus. Electrons move in orbits like the rings around Saturn
Niels Bohr believed that electrons move in a circular orbit at fixed distances from the nucleus
Sep 711:40 PM
Louis de Broglie proposed that moving particles like electrons have some properties of waves.
Erwin Schrodinger develops mathematical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model.
Review topic 2 Underlying structures of matter with answers.notebook
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February 07, 2018
Sep 89:18 PM
Questions
1. State Dalton's atomic theory.
a. All elements are composed of tiny indivisible particles called atoms.
b. Atoms of the same element are identical. The atoms of any one element are different from those of any other element.
c. Atoms of different elements can physically mix together or can chemically combine in simple wholenumber ratios to form compounds.
d. Chemical reactions occur when atoms are separated, joined, or rearranged. Atoms of one element, however, are never change into atoms of another element as a result of a chemical reaction.
Sep 89:26 PM
2. For the subatomic particles (electron, proton, neutron) indicate where they are located in an atom, their electrical charge, and their mass.
Subatomic Particle Location Electrical
Charge Mass
Electron
Outside the nucleus
(electron cloud)
NegativeVery Small (1/1840 of hydrogen atom)
Proton Nucleus Positive 1
Neutron Nucleus Neutral 1
Sep 89:35 PM
3. What is the overall charge of an atom? Explain how this possible?
The overall charge of an atom is neutral.
This is possible because in an atom the number of protons ALWAYS equals the number of electrons.
4. In your own words, briefly explain Rutherford's gold foil experiment?
Alpha particles (positive particles) were directed at a very thin sheet of gold foil.
The alpha particle should have passed through the gold, with only a small deflection due to the positive charge thought to be spread out in the gold atoms.
However, most of the alpha particles passed straight through the gold atoms, without deflection. Also, a small fraction of the alpha particles bounced off the gold foil at very large angles. Some even bounced back at the source.
He concluded that the atom is mostly empty space, thus explaining the lack of deflection. He concluded that all the positive charge and almost all of the mass are concentrated in the nucleus.
Sep 89:54 PM
5. Describe Rutherford's atomic model (nuclear model).
The protons and neutrons are located in the nucleus. The electrons are distributed around the nucleus and occupy almost all the volume (space) of an atom.
6. Provide a formula for determining the number of neutrons in an atom.
Neutrons = Mass Number atomic number (#protons)
7. Name two ways that isotopes of an element differ. How are they similar?
Same number of electrons and protons. (chemically identical)
Different number of neutrons.
8. What is the difference between mass number and atomic mass?
Mass number is the total number of protons and neutrons. (No decimals)
Atomic mass is a weighted average mass of the atoms in a naturally occurring sample of the element.
Sep 810:09 PM Sep 810:11 PM
2. How many protons and electrons are in each of the following atoms?a. magnesium (Atomic number = 12) b. silver (Atomic number = 47)
Review topic 2 Underlying structures of matter with answers.notebook
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February 07, 2018
Sep 1511:17 AM Sep 810:13 PM
Section 41 Section Assessment
Sep 810:18 PM
Practice Problems Section 43 Page 111
Sep 810:21 PM
Sep 810:25 PM
Section 43 Page 112 Practice Problem
Sep 810:26 PM
Review topic 2 Underlying structures of matter with answers.notebook
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February 07, 2018
Sep 810:21 PM
Section 43 Practice Problem Page 113
Sep 810:23 PM
Sep 810:24 PM
Section 43 Assessment page 119
Sep 810:09 PM
Sep 1310:52 PM
