1.
According to some scientists, the Earth's average, surface temperature is rising as a result of the green house effect. Increase in the atmospheric concentration of which of the following gases is considered to be primarily responsible?
Correct Answer
D. Carbon Dioxide
Explanation
The correct answer is Carbon Dioxide. According to scientists, the Earth's average surface temperature is rising due to the greenhouse effect, and an increase in the atmospheric concentration of Carbon Dioxide is primarily responsible for this phenomenon. Carbon Dioxide is a greenhouse gas that traps heat in the Earth's atmosphere, leading to global warming.
2.
Finding that a solution conducts an electric current shows conclusively that the solution
Correct Answer
D. Contains ions
Explanation
The fact that a solution conducts an electric current indicates that it contains ions. When a substance dissolves in water, it can break apart into charged particles called ions. These ions are responsible for carrying the electric current through the solution. Therefore, if a solution conducts electricity, it must contain ions.
3.
1. Boron atom, atomic, number 5, atomic mass 13
II. Carbon atom, atomic number 6, atomic mass 11
III. Carbon atom, atomic number 6, atomic mass 12
IV. Nitrogen atom, atomic number 7, atomic mass 13
Consider the atoms described above. Which of the
following are isotopes of each other?
Correct Answer
B. II and III only
Explanation
Isotopes are atoms of the same element that have different atomic masses. In this case, only options II and III are isotopes of each other because they are both carbon atoms with the same atomic number (6), but different atomic masses (11 and 12). Option I is a boron atom, and option IV is a nitrogen atom, so they are not isotopes of each other.
4.
Some substances have no noticeable odor because
these substances
Correct Answer
C. Have relativity few molecules escaping into the air
Explanation
Substances with no noticeable odor have relatively few molecules escaping into the air. Odor is detected when molecules from a substance enter the nose and interact with receptors in the olfactory system. If there are only a small number of molecules escaping into the air, the concentration of these molecules in the surrounding environment is low, making it difficult for the nose to detect any odor. Therefore, substances with few molecules escaping into the air will not have a noticeable odor.
5.
Several vehicles, initially at a complete stop, begin a
long race at the same starting point. The vehicle that has
a constant value for which of the following is most likely
to win?
Correct Answer
C. Linear acceleration
Explanation
The vehicle that has a constant value for linear acceleration is most likely to win the race. Linear acceleration measures how quickly an object's velocity changes over time. In the context of a race, a vehicle with a constant linear acceleration will be able to steadily increase its speed and velocity, allowing it to cover more distance in a shorter amount of time. This gives it an advantage over vehicles with varying or lower linear acceleration values.
6.
Which of the following statements is true of hurricanes
but not of tornadoes?
Correct Answer
A. They form only over warm oceans.
Explanation
Hurricanes form only over warm oceans because they require warm, moist air to fuel their development. Tornadoes, on the other hand, can form over land and do not have a specific requirement for warm ocean temperatures. The other statements, such as having high winds and causing property damage and fatalities, can apply to both hurricanes and tornadoes.
7.
The agent most widely and most consistently at work
changing the appearance of the Earth’s surface is.
Correct Answer
C. Water
Explanation
Water is the correct answer because it is the agent that has the greatest impact on changing the Earth's surface. Water can erode rocks and soil, create canyons and valleys, and shape coastlines through processes like erosion, weathering, and deposition. It can also cause floods and landslides, further altering the landscape. Additionally, water plays a crucial role in the formation of landforms such as rivers, lakes, and glaciers. Overall, the consistent and widespread presence of water on Earth makes it the most influential agent in changing the Earth's surface.
8.
A gelatinous sample of material from a previously
unexplored marine environment is thought to be living or
to be composed of recently living material. Which of the
following would most clearly confirm that the material
has a biological origin?
Correct Answer
A. The presence of cells in the sample
Explanation
The presence of cells in the sample would most clearly confirm that the material has a biological origin. Cells are the basic structural and functional units of living organisms, and their presence indicates the presence of life. Therefore, if the gelatinous sample contains cells, it strongly suggests that the material is either living or composed of recently living material.
9.
Which of the following is most directly involved with
controlling levels of sugar in blood?
Correct Answer
D. Insulin
Explanation
Insulin is most directly involved in controlling levels of sugar in the blood. Insulin is a hormone produced by the pancreas that helps regulate glucose metabolism. It acts by facilitating the uptake of glucose from the bloodstream into cells, where it can be used for energy or stored as glycogen. Insulin also inhibits the release of glucose from the liver and promotes the storage of excess glucose as fat. Therefore, insulin plays a crucial role in maintaining stable blood sugar levels by promoting the uptake and storage of glucose in the body's cells.
10.
In which of the following is the battery short-circuited?
Correct Answer
B. B
Explanation
The battery is short-circuited in option B.
11.
A piece of paper that appears blue in sunlight is illuminated solely by a red light that is passed through a green filter. What color does the paper appear und4er this illumination?
Correct Answer
D. Black
Explanation
When a red light is passed through a green filter, it absorbs all the red light and only allows green light to pass through. Since the paper appears blue in sunlight, it means that it reflects blue light and absorbs all other colors. In this case, when the paper is illuminated by red light passing through a green filter, it will absorb all the red light and only reflect or transmit green light. Therefore, the paper will appear black under this illumination.
12.
What quantity of oxygen, O2, contains very nearly the same number of molecules as 36.0 grams of water, H20?
Correct Answer
B. 32.0 grams
Explanation
The molar mass of water (H2O) is approximately 18.0 grams/mol. Since oxygen (O2) makes up about 32.0 grams/mol of the molar mass of water, we can conclude that 36.0 grams of water contains approximately 32.0 grams of oxygen. Therefore, the quantity of oxygen (O2) that contains the same number of molecules as 36.0 grams of water is 32.0 grams.
13.
In an experiment to study the effect of a new fertilizer on the
growth of tall hybrid corn and dwarf hybrid corn, from
immediately after germination to ten days of growth, the data
below were obtained. Other growing conditions such as
water and sunlight were the same for both groups.
Which of the following is the most reasonable
conclusion that can be drawn from the data above?
Correct Answer
A. The new fertilizer influences the growth of both corn varieties tested
Explanation
The given data shows that both the tall hybrid corn and dwarf hybrid corn experienced growth after the application of the new fertilizer. This suggests that the new fertilizer has an effect on the growth of both corn varieties.
14.
The Earth’s seasons can be attributed primarily to which
of the following in conjunction with its revolution about
the Sun?
Correct Answer
A. The tilt of the Earth’s axis of rotation relative to the
ecliptic
Explanation
The Earth's seasons are primarily attributed to the tilt of the Earth's axis of rotation relative to the ecliptic. This tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year, leading to the changes in temperature and weather patterns that we experience as seasons. The varying amount of sunspot activity, the Earth's orbit as an ellipse, and the rotation of the Earth during a 24-hour day do not directly cause the seasons.
15.
Of the following, which atom has the smallest atomic
radius?
Correct Answer
A. S
Explanation
Sulfur (S) has the smallest atomic radius among the given options. Atomic radius refers to the size of an atom, and it is determined by the distance between the nucleus and the outermost electron shell. In general, atomic radius decreases across a period from left to right on the periodic table. Sulfur is located to the right of sodium (Na) and barium (Ba) in the periodic table, so it has a smaller atomic radius compared to these elements.
16.
Animals in which of the following groups may have a
backbone and a spinal cord?
Correct Answer
B. Chordates
Explanation
Chordates are the only group mentioned that may have a backbone and a spinal cord. Mollusks, invertebrates, and echinoderms do not have these characteristics.
17.
Which of the following parts of the Sun is easily visible
only during a total solar eclipse?
Correct Answer
D. Corona
Explanation
During a total solar eclipse, the Moon aligns perfectly between the Earth and the Sun, blocking the Sun's bright photosphere and allowing the much fainter corona to become visible. The corona is the outermost layer of the Sun's atmosphere, extending millions of kilometers into space. It appears as a glowing halo around the darkened disk of the Moon during a total solar eclipse. The core, photosphere, and sunspots are all visible at other times, but the corona is only visible during a total solar eclipse when the photosphere is blocked.
18.
The true length of a block of wood is 1.010 cm. Three
measurements of this block produced the following
values: 1.4 cm, 1.2 cm, and 0.9 cm. Which of the
following statements is true concerning these
measurements?
Correct Answer
D. They are neither precise nor accurate
Explanation
The measurements of the block of wood are neither precise nor accurate because they do not consistently match the true length of 1.010 cm. Precise measurements would have very little variation between each other, while accurate measurements would closely match the true value. In this case, the measurements have both variation and do not match the true length, indicating that they are neither precise nor accurate.