Vocab
Anything that has mass and occupies space.
In this state of matter, particles are tightly packed in a fixed, orderly arrangement and cannot move past each other.
What is a solid?
A snowball sitting at the top of a snowy hill before anyone pushes it.
What is potential energy?
When ice cubes are placed in a glass of warm lemonade, energy flows in this direction.
What is from the surroundings (lemonade) into the system (ice)?
Which molecule is NOT a compound?
O₂, H₂O, CO₂, or NaCl.
What is O₂?
The fundamental building blocks of matter; the smallest representative unit of an element.
What are atoms?
In this state of matter, particles are close together but can "slide" past each other and take the shape of their container.
What is a liquid?
Molecules of steam (water vapor at 100°C) escaping from a boiling kettle and moving rapidly through the air.
What is thermal energy (also accept kinetic energy)?
A campfire is burning wood. Energy flows in this direction, and this type of reaction is occurring.
What is from the system (wood) into the surroundings (air/environment)?
The total kinetic energy of all the particles that make up matter.
What is thermal energy?
The simplest form of matter that has a characteristic set of properties.
What is an element?
In this state of matter, particles are far apart, move freely, and are not held together by attractive forces.
What is a gas?
During photosynthesis, plants absorb light energy to convert CO₂ and H₂O into glucose (C₆H₁₂O₆). The glucose stores this type of energy.
What is chemical potential energy?
A beaker of room-temperature water is placed on a hot plate and begins to boil. The system is the water. Identify the surroundings and the direction of energy flow.
What is: Surroundings = the hot plate (and air), and energy flows from the surroundings into the system?
A cold pack is activated by breaking an inner pouch, causing ammonium nitrate to dissolve in water. The pack feels cold on your skin. Identify the system and surroundings in this scenario.
What is:
System: the cold pack (or the chemicals/water inside the cold pack)
Surroundings: your skin (and the air around the pack)?
When two or more atoms combine and are held together by chemical bonds.
What is a molecule?
These two factors determine what state of matter a substance is in: the attractive forces holding particles together and this.
What is the motion/movement of the particles?
A skydiver jumps from a plane.bRight before they jump, they have maximum ______ energy. As they fall and accelerate an energy conversion occurs. Just before the parachute opens they have maximum ________ energy.
Question: What is potential energy converting to kinetic energy?
An ice cube is removed from the freezer and left on a kitchen counter. After 10 minutes, it has completely melted into liquid water. The system is the ice/water.
Identify the direction of energy flow and two macroscopic properties that changed in the system.
What is: Energy flows from the surroundings (counter/air) into the system, and phase changed (solid to liquid) and temperature increased in the system?
The capacity to move, do work, change matter, or produce heat.
What is energy?
A characteristic that is large enough to see, handle, or measure without magnification, such as color, density, temperature, or pressure.
What is a macroscopic property?
Why does ice float on water? Use concepts of density and particle arrangement in your response.
What is Ice floats on water because ice is less dense than liquid water. Ice is less dense than liquid water because the molecules are in a fixed pattern and there is more space between solid water molecules than liquid water molecules. Liquid water molecules are more closely packed together making them more dense.
When you strike a match against the matchbox, the friction causes the chemicals in the match head to ignite and burn. This type of energy stored in the match head is converted into this type of energy.
What is chemical potential energy converted into thermal energy?
A student eats a sandwich for lunch. Identify where this energy is stored, what happens to it during digestion, and the direction of energy flow when it's used by the body.
What is: Energy is stored in the chemical bonds of the food molecules, it is released during digestion (breaking bonds), and energy flows from the system (food/body cells) into the surroundings (used for movement, heat, body functions)?
Explain the relationship between atoms, molecules, elements, and compounds in 2–3 sentences.
What is: All matter is made of atoms. Atoms of only one type with specific properties are called elements. When two or more atoms bond together, they form molecules. When different types of atoms bond together, they form compounds?