Stars and Sun
What role does the Sun play in our solar system, and why is it considered the center of it?
The Sun provides the gravitational force that keeps all the planets in orbit and is the main source of energy for the solar system
What do waves transfer?
Energy
A student observes that salt helps ice melt faster on roads. They create a hypothesis and design an experiment. What are three things they must do to make sure the experiment is fair and results are reliable?
Test multiple times (replication), keep variables controlled, measure with appropriate tools, and clearly record procedures and results
What is the main source of energy that powers the water cycle?
The Sun
What does the atomic number of an element tell you?
The number of protons in the nucleus
How do gravity and inertia work together to keep planets moving in orbit around the Sun?
Gravity pulls planets toward the Sun, while inertia (their forward motion) keeps them moving in a curved path around it.
What’s one main difference between how light (electromagnetic) and sound (mechanical) waves travel?
Light can travel through space; sound needs a medium
A student wants to test how the type of liquid affects how fast a plant grows. Identify the independent, dependent, and one controlled variable.
Independent = type of liquid; Dependent = plant growth rate; Controlled = amount of sunlight, type of plant, container, soil
Why are decomposers like fungi and bacteria important to nutrient cycles?
They recycle the nutrients when they break down dead organisms, returning nutrients to the soil and atmosphere for plants to use.
What do all elements in the same group (column) have in common?
They have the same number of valence electrons and similar chemical properties
Explain how the Sun produces energy and how this energy travels to Earth.
The Sun produces energy through nuclear fusion in its core, hydrogen is fused into helium, and the energy travels to Earth as electromagnetic radiation, including light and heat.
Why does sound travel faster through solids than through gases?
Particles are packed closer together in solids, allowing vibrations to move faster
In science, what is a model and how is it used. Describe what a limitation of a model is and give an example.
Models help simulate or represent systems (e.g., atoms, ecosystems, space); limitations include simplification and lack of real-world variability
Ex. Solar system model that does not accurately represent the scale of the planets
What role do nitrogen-fixing bacteria play in the nitrogen cycle
They convert nitrogen gas from the atmosphere into forms plants can use (Nitrates and Nitrites).
What does it mean when an element is described as a "metal," and where are most metals located on the periodic table?
Metals are good conductors of heat and electricity and are mostly located on the left and center of the periodic table
Describe how the Sun and Moon each affect tides on Earth. Include the difference between spring and neap tides.
Both the Sun and Moon’s gravity pull on Earth’s oceans; the moon has a greater influence because it is closer. When all are aligned (new/full moon), they cause spring tides (stronger); when at right angles (first/third quarter), they cause neap tides (weaker)
Describe an example of energy transformation in a microwave oven.
Electrical energy (outlet) transforms into electromagnetic (microwave) energy and then thermal energy (heat) in food
Two scientists perform the same experiment but get different results. What are 3 steps should they take to resolve the differences, and what does this show about scientific knowledge?
They should compare procedures, check for errors, replicate trials, and share data; it shows scientific knowledge is open to change based on new evidence
Draw the carbon cycle, include all major processes that contribute to the recycling of carbon in Earth’s spheres.
Drawing must include Photosynthesis turning CO2 into Glucose. Cellular respiration turns glucose into CO2. Decomposition turns carbon into fossil fuels. Fossil fuel burning returns C02 to the atmosphere.
Why are elements in Group 18 called noble gases, and how do they differ from other groups?
They have full outer electron shells (8 electrons), making them stable and unreactive compared to other elements