Can someone check these?
1. What device, developed in 1970, is able to make images of individual atoms?
1. The X-ray crystallographer
2. The laser
3. The Brownian motion detector
4. The scanning electron microscope
My answer: 4
2. Which of the following is smallest?
1. Proton
2. Electron
3. Nucleus
4. Atom
atom?
3. The chemical formula for human insulin is C257H383N65O77S6. How many atoms of Nitrogen does it contain?
1. 65
2. 77
3. 257
4. 383
My answer: 65
4. Copernicus proposed his theory because it fit Tycho Brahe's data concerning planetary positions, whereas Ptolemy's theory did not fit Brahe's data.
True
False
True?
5. According to the sun-centered viewpoint of Copernicus, why does the sun appear to rise in the east and set in the west?
1. The earth orbits the sun once a day from west to east, so the sun appears in the east and disappears in the west.
2. The sun spins on its axis once a day from east to west and so it appears in the east and disappears in the west.
3. The sun orbits the earth once a day from west to east and so it appears in the east and disappears in the west.
4. he earth spins on its axis once a day from west to east and so the sun appears in the east and disappears in the west.
My answer:2
6. Our Milky Way galaxy contains perhaps 400 billion stars. Suppose that 0.05% (i.e., 0.000 5) of these stars have planetary systems containing at least one Earthlike planet (one that could conceivably support Earthlike life). Express this number in words (thousands or millions, etc.).
1. 20 billion
2. 20
3. 200 million
4. 20 thousand
my answer: 3?
7. The ancient Greeks noted that the planets moved in step with the stars, without changing their positions among the stars.
True
False
I thinks its false
8. Darwin's principles of biological evolution are just a theory. This means that evolution is
1. easily proven wrong by pointing out some simple observations or flaws in the scientific method.
2. an idea that was invented in order to oppose creationism.
3. an educated guess or hypothesis.
4. an explanation for what is observed based on overwhelming evidence.
my asnwer: 3
9. From the fact that the carbon atom is 12 times heavier than the hydrogen atom, we can conclude that the weight ratio of carbon to hydrogen in the formation of methane (CH4) is 4 to 1.
True
False
I think its true
10. Wolfgang Pauli, a famous physicist of the twentieth century, is credited with saying of an idea that, "it is not even wrong!" Which of the following statements is most likely to be what he meant?
1. The idea was untested and scientific.
2. The idea was correct and thus scientific.
3. The idea was testable and non-scientific.
4. The idea was untestable and non-scientific.
I think 2
Numbers 2,5, 8 9, 10. are wrong.
Number 7 is confusing in the statement, so much so, I cant decipter. "moved in step with the stars, without changing their positions among the stars" is a very confusing and ambigious statement.
1. The device developed in 1970 that is able to make images of individual atoms is the scanning electron microscope.
To arrive at this answer, you can eliminate the other options by understanding their respective functions:
- The X-ray crystallographer is a tool used to determine the atomic and molecular structure of a crystal, not to image individual atoms.
- The laser is a device that emits light through a process called stimulated emission, and it is not used specifically for imaging individual atoms.
- The Brownian motion detector is a device used to observe and measure the random motion of microscopic particles suspended in a fluid, which is unrelated to imaging individual atoms.
2. The smallest entity among the options given is the electron.
To determine this, we need to understand the structure of an atom:
- An atom consists of a central nucleus composed of protons and neutrons, surrounded by electrons.
- Protons are positively charged particles found in the nucleus.
- Electrons are negatively charged particles that orbit the nucleus.
- The nucleus is much smaller than the whole atom, and electrons are even smaller than the nucleus.
3. The chemical formula for human insulin (C257H383N65O77S6) tells us that it contains 65 atoms of nitrogen.
To count the number of atoms of nitrogen, we can find the subscript of N (representing nitrogen) in the chemical formula.
4. The statement "Copernicus proposed his theory because it fit Tycho Brahe's data concerning planetary positions, whereas Ptolemy's theory did not fit Brahe's data" is True.
To arrive at this answer, we need to understand the context:
- Copernicus proposed the heliocentric theory, which suggests that the sun is at the center of the solar system and the planets revolve around it.
- Tycho Brahe was an astronomer who collected detailed and accurate observational data on planetary positions.
- Copernicus' heliocentric theory was consistent with Brahe's data, while Ptolemy's geocentric theory (which places Earth at the center of the solar system) did not align with Brahe's observations.
5. According to the sun-centered viewpoint of Copernicus, the sun appears to rise in the east and set in the west because the Earth spins on its axis once a day from west to east, so the sun appears in the east and disappears in the west.
To determine this, we need to understand the motion of celestial bodies according to the heliocentric model proposed by Copernicus:
- The Earth rotates on its axis, completing one full rotation in approximately 24 hours.
- As the Earth rotates, different parts of its surface face the sun, resulting in the appearance of the sun rising in the east and setting in the west.
6. Expressing the number "0.05%" (0.0005) of 400 billion stars containing Earthlike planets as a worded quantity would be "20 million."
To calculate this, we can multiply 0.05% by 400 billion:
0.05% = 0.05/100 = 0.0005
0.0005 * 400 billion = 200 million
7. The statement "The ancient Greeks noted that the planets moved in step with the stars, without changing their positions among the stars" is False.
This statement is incorrect or misleading, as the ancient Greeks actually observed that planets moved relative to the fixed backdrop of stars, gradually changing their positions among the stars over time. The realization of this led to the development of heliocentric models by astronomers like Copernicus.
8. Darwin's principles of biological evolution as a theory mean that evolution is an explanation for what is observed based on overwhelming evidence.
To understand this, we need to clarify the meaning of "theory" in a scientific context:
- In science, a theory is not an unproven guess or hypothesis but a well-substantiated explanation for a set of phenomena, supported by a considerable body of evidence.
- Darwin's principles of biological evolution, supported by extensive observations and experiments, explain the diversity and adaptation of species over time.
9. The statement "From the fact that the carbon atom is 12 times heavier than the hydrogen atom, we can conclude that the weight ratio of carbon to hydrogen in the formation of methane (CH4) is 4 to 1" is False.
To determine this, we need to consider the molecular formula of methane (CH4):
- The molecular formula CH4 means there is one carbon atom and four hydrogen atoms in a molecule of methane.
- Comparing the atomic masses, one carbon atom has an atomic mass of approximately 12 atomic mass units (amu), while one hydrogen atom has an atomic mass of approximately 1 amu.
- Therefore, the weight ratio of carbon to hydrogen in methane is 12 to 4, which simplifies to 3 to 1, not 4 to 1.
10. The statement "Wolfgang Pauli is credited with saying of an idea that, 'it is not even wrong!'" implies that the idea was untestable and non-scientific.
To understand this, we need to grasp the meaning behind the phrase "not even wrong":
- The phrase originated from Wolfgang Pauli, a physicist, who used it to describe ideas or theories that lack the necessary evidence, logical consistency, or testability required to be considered scientific.
- By saying an idea is "not even wrong," Pauli indicates that it fails to meet the basic criteria for being valid within the scientific framework.