Atomic Chemistry (7%) Flashcards
(28 cards)
The atomic mass of carbon is 12 and the atomic mass of hydrogen is 1. What is the percent by mass of carbon in methane gas, CH4?
(A) 20% (B) 25% (C) 50% (D) 75% (E) 80%
(D) 75%
Calculation: C(12) + H(1) + H(1) + H(1) + H(1) = 16 (total atomic mass of CH4). 12 (total carbon) / 16 (total mass of CH4) = 0.75 (75%)
The notation 1s(superscript 2)2s(superscript 2)2p(superscript 4) represents
(A) a noble gas (B) an atomic nucleus (C) an element with 8 protons (D) an element with 8 electrons (E) an element with an oxidation state of 4
(D) an element with 8 electrons
Reason: The superscript represents the number of electrons in the subshell.
Which of the following correctly identifies the constituents of an atom of the isotope 131/53 I?
(A) 53 Protons | 78 Neutrons | 78 Electrons
(B) 78 Protons | 53 Neutrons | 78 Electrons
(C) 53 Protons | 78 Neutrons | 53 Electrons
(D) 78 Protons | 131 Neutrons | 78 Electrons
(E) 131 Protons | 53 Neutrons | 53 Electrons
(C) 53 Protons | 78 Neutrons | 53 Electrons
Reason: Iodine has 53 Protons (atomic number) and 53 Electrons (equals protons). Subtracting 53 Protons from 131 (atomic mass) = 78 Neutrons.
Which of the following are found in greater number in the nuclei of carbon-14 atoms than in the nuclei of carbon-12 atoms?
(A) Alpha particles (B) Positrons (C) Neutrons (D) Protons (E) Electrons
(C) Neutrons
Water has a higher boiling point than hydrogen sulfide because water has strong
(A) ionic bonds (B) covalent bonds (C) hydrogen bonds (D) ion-dipole forces (E) London dispersion forces
(C) hydrogen bonds
Which of the following types of decay does not change the mass number of the element?
(A) alpha decay (B) beta decay (C) gamma radiation (D) a and b (E) b and c
(E) b and c
Beta decay and Gamma Radiation
The half-life of 14/6 C is 5,600 years. Which of the following statements about a 10-gram sample of 14/6 C is correct?
(A) The radioactive decay of the sample will be complete after 5,600 years.
(B) The sample will start radioactive decay after 5,600 years.
(C) A time of 5,600 years has been required to produce this sample of 14/6 C in nature.
(D) After 5,600 years the sample will contain only 5 grams of 14/6 C
(E) After 11,200 years the sample will not contain any 14/6 C.
(D) After 5,600 years the sample will contain only 5 grams of 14/6 C
Scientists will use what is called the _____ to determine if something is true or a natural law.
(A) Theoretical method
(B) Scientific method
(C) Probability method
(D) Hypothesis method
(B) Scientific method
All matter is made up of building blocks called
(A) Neutrons
(B) Protons
(C) Atoms
(D) Electrons
(C) Atoms
A _____ cannot be broken down into any other substance.
(A) Electron
(B) Element
(C) Proton
(D) Neutron
(B) Element
A(n) _____ is the simplest unit of an element that retains the elements characteristics.
(A) Atom
(B) Electron
(C) Proton
(D) Neutron
(A) Atom
Hydrogen and Oxygen are both _____; water is a _____.
(A) Molecules, element
(B) Elements, compound
(C) Electrons, neutron
(D) Electrons, proton
(B) Elements, compound
Atoms consist of a small, densely packed _____ composed of positively charged protons and neutrally charged neutrons, surrounded at its periphery by clouds of negatively charged electrons.
(A) Element
(B) Molecule
(C) Nucleus
(D) Cell
(C) Nucleus
The outer shell of any atom is called the
(A) Exterior shell
(B) Protective shell
(C) Valence shell
(D) Outer shell
(C) Valence shell
The valence shell can have a maximum of _____ electrons.
(A) 2
(B) 4
(C) 6
(D) 8
(D) 8
Elements are arranged on the periodic table by _____, or the number of _____ in the nucleus.
(A) Atomic mass, protons
(B) Atomic number, neutrons
(C) Atomic mass, neutrons
(D) Atomic number, protons
(D) Atomic number, protons
If you change the number of protons, you have changed the element to something completely different. So the number of protons is never really going to change.
(A) True
(B) False
(A) True
Elements that have the same number of protons, but a different number of neutrons are _____ of each other. (Like Carbon 13).
(A) Isotopes
(B) Subshells
(C) Resistive
(D) Groups
(A) Isotopes
Protons + neutrons + electrons =
(A) Atomic number
(B) Atomic mass
(B) Atomic mass
Reason: The mass of an atom is the sum of the masses of all of the particles that compose that atom.
Protons and neutrons each have a mass of _____ AMU (atomic unit), but electrons are so small, their mass is considered to be negligible, or 0.
(A) 1
(B) 2
(C) 3
(D) 4
(A) 1
In the periodic table, _____ is the magic number in terms of the valence shell configuration for an element. We want an element that has a valence shell configuration of _____ because it is the most stable.
(A) 2
(B) 4
(C) 6
(D) 8
(D) 8
In the periodic table, the group numbers (1,2 and 13-18 (minus 10)) represent the number of _____ that the elements in that group contain.
(A) Valence shell neutrons
(B) Valence shell protons
(C) Valence shell electrons
(C) Valence shell electrons
The periodic table is separated into group numbers, in the columns labeled 1, 2, and 13–18. Group 1 has a 1 valence shell electron (1 electron on the outermost shell of the atom). Group 2 has 2 valence shell electrons. Moving over, Group 13 has 3 valence shell electrons. Group 14 has 4, Group 15 has 5, Group 16 has 6, Group 17 has 7, and Group 18 has 8.
Sometimes the nuclei of an atom is unstable, and releases one or more subatomic particles in order to become more stable. When this happens, an element is said to be
(A) Radioactive
(B) Subatomic
(C) Radial
(D) Atomic
(A) Radioactive
The three common modes of decay from radioactive nuclei are
(A) Alpha decay, beta decay, and delta decay
(B) Alpha decay, beta decay, and delta radiation
(C) Alpha decay, beta decay, and gamma decay
(D) Alpha decay, beta decay, and gamma radiation
(D) Alpha decay, beta decay, and gamma radiation
