Chem 4 – Space – Flashcards
Unlock all answers in this set
Unlock answersquestion
Why can't we see atoms?
answer
We see with light energy and the wavelength is larger than the object and so it is not reflected.
question
Which of the following could NOT be represented by a conceptual model?
answer
the floor plan of a house
question
What is the main difference between a conceptual model and a physical model?
answer
A physical model represents the shape and form while a conceptual model describes how a system behaves.
question
What prompted early scientists to propose that the ray of the cathode ray tube was due to the cathode?
answer
The ray was present regardless of gas, or even without a gas.
question
Which of the following determined the ratio of the charge of an electron to its mass?
answer
J.J. Thompson's cathode ray deflection experiments
question
Which of the following experiments helped to determine the charge of an electron and (indirectly) its mass?
answer
R. Millikan's oil drop experiments
question
What prompted early scientists to propose that the ray of the cathode ray tube was actually a negatively charged particle?
answer
The ray was attracted to positively charge electric plates.
question
Since atoms are mostly empty space, why don't objects pass through one another?
answer
The electrons on the atoms repel other electrons on other atoms when they get close.
question
In Rutherford's gold foil experiment, alpha particles ________.
answer
were deflected by the atomic nucleus
question
Which of the following statements does not describe a proton?
answer
It orbits around the nucleus of an atom.
question
Which of the following does not describe a neutron?
answer
It has a positive charge equivalent but opposite of an electron's.
question
The following statement describes which subatomic particle best? It does not have an electrical charge.
answer
a neutron
question
Which element has the atomic number 9?
answer
F
question
Which of the following statements describes an isotope?
answer
element with the same number of protons but a different number of neutrons
question
The mass number of an element is ________.
answer
the sum of the protons and the neutrons
question
What does the following element description actually mean? hydrogen-2
answer
a hydrogen with one neutron and one proton
question
What does the following element description actually mean? 238 92 U
answer
a uranium atom with 92 protons and 146 neutrons.
question
Does it make sense to say that a textbook is about 99.9 percent empty space?
answer
Yes. A textbook like all material things is made up of atoms, which are considered to be 99.9% empty space.
question
If an element has 15 protons and 16 neutrons and 15 electrons, what is the mass number of the element?
answer
31
question
If an element has 18 protons and 20 neutrons and 18 electrons, which expression correctly identifies the element?
answer
argon-38
question
If an element has 9 protons and 10 neutrons and 9 electrons, which expression correctly identifies the element?
answer
19 F 9
question
If a neutral element has the following chemical notation, how many electrons does it have? carbon-13
answer
6
question
If a neutral element has the following chemical notation, how many electrons does it have? fluorine-19
answer
9
question
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 ________.
answer
become arsenic
question
Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom?
answer
C
question
If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?
answer
atomic mass, 99 amu; Technetium
question
The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?
answer
26
question
Why are the atomic masses listed in the periodic table not whole numbers?
answer
The atomic masses are average atomic masses
