Matter & Its Interactions
Explain why the presence of bubbles when boiling water is a physical change, but the presence of bubbles when mixing baking soda and vinegar is a chemical change.
-Boiling water is a change of state, evaporation
-The baking soda+vinegar create bubbles due to a new gas forming from the chemical reaction.
About 97% of Earth's water is salt water. Of the remaining 3% that is freshwater, where is the majority of it trapped or located?
It is frozen in glaciers and ice caps.
What are the nonrenewable energy sources that are most commonly used in the U.S, and what is the primary byproduct when burning it?
Fossil Fuels (Oil, Coal, & Natural Gas). The primary byproduct is carbon dioxide, which contributes to global warming.
In 2014,the Ebola virus was concentrated in West Africa, affecting neighboring countries. What term best describes this outbreak?
What is an epidemic?
In the winter, the fur of the arctic fox is white. In summer, the fur darkens to a reddish brown. What most likely causes the fur of the fox to change color?
The fox's genes. Adaptations helped it survive.
Methane exists as a pure gas. It is composed of one carbon atom and four hydrogen atoms bonded together. How is methane classified as?
What is a compound?
What is a river basin, and how does it differ from a stream?
A river basin is the entire land area that drains into a large river. A stream is just one small channel of water within that larger basin
What are the two specific characteristics an organism must have to be considered a good index fossil?
They must have lived for a short period of time and been found in many different places (widely distributed)
Identify the type of pathogen that causes Malaria and describe the role of the mosquito in the spread of this disease.
Malaria is caused by a parasitic protist. The mosquito is a vector, meaning it carries and transmits the pathogen from one host to another without being sick itself.
A strawberry farmer finds that, after a harsh winter, some of his strawberries are still alive. Which best explains why these strawberries were able to survive?
They have different genetic variations that cause them to be more resistant to cold temperatures.
Look at the following unbalanced equation for the reaction of Aluminum and Oxygen: Al+O2→Al2O3. What coefficients are needed for both reactants and the product to balance this equation?
4 in front of Al, 3 in front of O2, and 2 in front of Al2O3.
Describe the relationship between salinity, temperature, and water density in the deep ocean.
Cold water and high-salinity water are more dense, causing them to sink. This creates deep-sea currents that drive global ocean circulation.
Explain the concept of stewardship in terms of energy and provide one example on how to conserve energy.
Stewardship is the responsible management, efficient use, and sustainable development of energy to meet needs without using it up for future generations. *Answers may vary for how to conserve energy.
A disease wipes out the majority of the apex predators. How will this most likely affect the primary consumers in that ecosystem?
Their population will increase rapidly due to a lack of predation, eventually leading to overconsumption of producers.
A farmer uses a new pesticide to kill 99% of the insects eating his crops. He uses the same pesticide next year, but this time it only kills 50% of the insects. By the third year, the pesticide doesn't work at all. Explain why the pesticide became useless.
Natural selection. The first spray killed all insects except those few who had a natural, genetic mutation that made them resistant. Those survivors were the only ones left to breed. By the third year, the entire population became resistant.
A liquid's boiling point rises from 78°C to 100°C while heating. Classify it.
What is a mixture?
Explain the relationship between water temperature and Dissolved Oxygen.
As water temperature increases, the amount of dissolved oxygen decreases. Cold water holds more oxygen than warm water.
Why is the fossil record considered incomplete? Provide at least two reasons why many ancient organisms never became fossils.
-Organism destroyed by erosion, melting, or crushing of rock layers
-Scavengers ate the bodies
-Volcanic activity
A forest is home to a healthy population of wild turkeys. A nearby logging operation clears a large section of the forest, but they leave all the berry bushes and nut-producing trees untouched. Despite the food supply remaining the same, the turkey population drops by 40% over the years. Identify the abiotic limiting factor most likely responsible for this population decline.
The logging removed the trees used for nesting and protection. Space is a critical abiotic factor that defines an ecosystem's carrying capacity.
A student is comparing the skeletal structure of a human arm, a whale flipper, and a bat wing. Even though these limbs look different on the outside and are used for different tasks, they all contain a similar arrangement inside. What is the term for these similar structures, and what do they specifically prove about the relationship between humans, whales, and bats?
Homologous Structures. These structures prove that these species share a common ancestor. Over time, natural selection led to these bones being modified for different uses.
Balance the following equation for the production of ammonia and explain how this balanced version supports the Law of Conservation of Mass.
N2+H2→NH3.
N2+3H2→2NH3. There are exactly 2 nitrogen atoms and 6 hydrogen atoms on both the reactant and product sides, proving no atoms were created or destroyed.
A city monitors a lake after a massive fertilizer spill:
>Day 1: Nitrates are high, Turbidity is low, and DO is normal
>Day 7: Turbidity is high, and DO is very high
>Day 14: DO has dropped to 2 mg/L
Explain the biological reason for the DO spike on Day 7, and identify what phenomenon occured.
The Day 7 DO spike was caused by an algal bloom due to high nitrates/phosphates from fertilizer. This is clled eutrophication.
There are four sedimentary layers (A,B,C,D) with an igneous intrusion cutting through the bottom three layers (D,C,& B) but not the top layer (A). Between layer B and layer A, there is a jagged, uneven line. If the igneous intrusion is dated ~250 million years old, what can you conclude about the age of Layer A and the cause of that jagged line?
Layer A must be younger than 250 million years. The jagged line is an unconformity, which proves that a period of erosion occurred, removing some of the rock record before Layer A was deposited.
A fungus provides a tree with nutrients. The tree provides the fungus with sugar. However, during a drought, the tree begins to stop sugar production to save itself, and the fungus begins to pull moisture directly out of the tree for survival. What best describes the shift in relationships? (think of organism relationships)
It demonstrates a shift from Mutualism to Parasitism.
Scientists recently discovered two different species of extinct ground-dwelling mammals in different rock layers of a canyon.
Species A was found in a deep rock layer (dated to 50 million years ago) and has a heavy jawbone with flat teeth and a short, thick humerus (upper arm bone).
Species B was found in a much shallower rock layer (dated to 10 million years ago) and has a lighter jawbone with similar flat teeth, but a much longer, thinner humerus.
How are these two species related?
The two mammals share an evolutionary relationship (common ancestor), where Species A is the older ancestor found in deeper rock, and Species B is the descendant that adapted to its environment over 40 million years through natural selection.