Question

a scientist observes that plants near a factory are growing slower than plants further away. which of the following is a testable hypothesis based on this observation?
the factory is causing the plants to grow slower.
pollution from the factory is bad for plants.
plants grow at different rates in different locations.
increased exposure to factory emissions inhibits plant growth.
which of the following statements is an example of an observation? *
the chemical reaction occurred because a catalyst was added.
the plant grew taller because it received more sunlight.
the rock is old because it is located deep underground.
the solution turned blue after the two liquids were mixed.
which of the following best defines an observation in the scientific method?
a judgment or interpretation based on evidence.
a proposed explanation for a phenomenon.
a testable statement used to predict future outcomes.
the act of noticing or perceiving something using the senses.

Explanation:

• First question: A testable hypothesis should be specific. "Increased exposure to factory emissions inhibits plant growth" can be tested by comparing plant growth with different levels of factory - emission exposure. The other options are either too vague (e.g., "Plants grow at different rates in different locations") or not specific about the factor (e.g., "The factory is causing the plants to grow slower" without specifying the cause from the factory, and "Pollution from the factory is bad for plants" is also too general).
• Second question: An observation is a factual statement about what is seen. "The solution turned blue after the two liquids were mixed" is a direct observation. The other options ("The chemical reaction occurred because a catalyst was added", "The plant grew taller because it received more sunlight", "The rock is old because it is located deep underground") are interpretations or explanations, not just observations.
• Third question: By definition, an observation in the scientific method is "The act of noticing or perceiving something using the senses". A judgment or interpretation based on evidence is an inference. A proposed explanation for a phenomenon is a hypothesis. A testable statement used to predict future outcomes is also related to a hypothesis.

Answer:

• First question: Increased exposure to factory emissions inhibits plant growth.
• Second question: The solution turned blue after the two liquids were mixed.
• Third question: The act of noticing or perceiving something using the senses.