Chem 4 – Space

Flashcard maker : Lily Taylor
Why can’t we see atoms?
We see with light energy and the wavelength is larger than the object and so it is not reflected.
Which of the following could NOT be represented by a conceptual model?
the floor plan of a house
What is the main difference between a conceptual model and a physical model?
A physical model represents the shape and form while a conceptual model describes how a system behaves.
What prompted early scientists to propose that the ray of the cathode ray tube was due to the cathode?
The ray was present regardless of gas, or even without a gas.
Which of the following determined the ratio of the charge of an electron to its mass?
J.J. Thompson’s cathode ray deflection experiments
Which of the following experiments helped to determine the charge of an electron and (indirectly) its mass?
R. Millikan’s oil drop experiments
What prompted early scientists to propose that the ray of the cathode ray tube was actually a negatively charged particle?
The ray was attracted to positively charge electric plates.
Since atoms are mostly empty space, why don’t objects pass through one another?
The electrons on the atoms repel other electrons on other atoms when they get close.
In Rutherford’s gold foil experiment, alpha particles ________.
were deflected by the atomic nucleus
Which of the following statements does not describe a proton?
It orbits around the nucleus of an atom.
Which of the following does not describe a neutron?
It has a positive charge equivalent but opposite of an electron’s.
The following statement describes which subatomic particle best? It does not have an electrical charge.
a neutron
Which element has the atomic number 9?
F
Which of the following statements describes an isotope?
element with the same number of protons but a different number of neutrons
The mass number of an element is ________.
the sum of the protons and the neutrons
What does the following element description actually mean? hydrogen-2
a hydrogen with one neutron and one proton
What does the following element description actually mean?
238
92
U
a uranium atom with 92 protons and 146 neutrons.
Does it make sense to say that a textbook is about 99.9 percent empty space?
Yes. A textbook like all material things is made up of atoms, which are considered to be 99.9% empty space.
If an element has 15 protons and 16 neutrons and 15 electrons, what is the mass number of the element?
31
If an element has 18 protons and 20 neutrons and 18 electrons, which expression correctly identifies the element?
argon-38
If an element has 9 protons and 10 neutrons and 9 electrons, which expression correctly identifies the element?
19
F
9
If a neutral element has the following chemical notation, how many electrons does it have? carbon-13
6
If a neutral element has the following chemical notation, how many electrons does it have? fluorine-19
9
You could swallow a capsule of germanium, Ge (atomic number 32), without significant ill effects. If a proton were added to each germanium nucleus, however, you would not want to swallow the capsule because the germanium would ________.
become arsenic
Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom?
C
If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?
atomic mass, 99 amu; Technetium
The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?
26
Why are the atomic masses listed in the periodic table not whole numbers?
The atomic masses are average atomic masses

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