Chemical Reactions
What is one sign that a chemical reaction may have happened?
Gas, color change, temperature change, or a new substance forms.
What tool do scientists use to measure temperature?
Thermometer
What is the basic unit of life?
A Cell
What is a stimulus?
Something in the environment that causes a response
What is evidence?
Information or data that supports an idea
During a chemical reaction, what happens to atoms?
They rearrange to form new substances.
What happens to temperature when particles move faster?
Temperature increases
What is a group of similar cells working together called?
A tissue
What is a response?
A reaction to a stimulus
What is a scientific model used for?
To represent or explain something in science
If the starting mass is 50 grams, what should the ending mass be in a closed system?
50 grams.
What is energy transfer?
Energy moving from one object or system to another
Put these in order from smallest to largest: organ system, cell, organ, tissue.
Cell, tissue, organ, organ system
If bright light makes your pupils get smaller, what is the stimulus?
Bright light
What should a good scientific explanation include?
A claim, evidence, and reasoning (CER)
Why does mass sometimes seem to decrease during a reaction?
Gas may escape if the system is open.
In a hand warmer, why does the temperature increase?
A chemical reaction releases energy to the surroundings
What body system sends signals and helps the body respond to the environment?
Nervous System
Which body system detects stimuli and sends messages through the body?
Nervous System
A graph shows temperature increasing over time. What pattern does the graph show?
The temperature is rising or increasing
Explain how human activity can affect an ecosystem.
Human activity can change habitats, resources, populations, and interactions.
Explain the difference between an endothermic and exothermic reaction.
An exothermic reaction releases energy and gets warmer. An endothermic reaction absorbs energy and gets cooler.
Explain how cells, tissues, organs, and organ systems work together in the body.
Cells make up tissues, tissues make up organs, organs work together in organ systems, and organ systems help the body carry out life functions.
Explain how the body responds when you touch something hot.
Receptors in the skin detect heat, the nervous system sends a message, and muscles move your hand away.
Why do scientists revise models?
Scientists revise models when they collect new evidence or find a better explanation.