States of matter
What state of matter takes the shape of its container but has a fixed volume?
Liquid
This is laments symbol is ‘O’ and is essential for respiration in most living organisms
Oxygen
When does a chemical change occur ?
when a substance transforms into a completely new substance with different chemical properties
What is an endothermic reaction?
any chemical reaction that absorbs heat from its environment
What is an exothermic reaction?
An exothermic reaction is a chemical reaction that releases energy
What is a solid?
The state of matter has a definite shape and volume.
What is the atomic number of hydrogen?
Hydrogen is a chemical element with symbol H and atomic number 1
Describe a chemical change that occurs in the human body.
A prominent chemical change in the human body is cellular respiration
Name a common endothermic reaction that occurs in everyday life.
A common endothermic reaction in everyday life is the melting of ice cubes
Name a common exothermic reaction that occurs in everyday life
A common exothermic reaction that happens in everyday life is combustion
What term describes the transition from liquid to solid?
Freezing
What is the lightest noble gas?
The lightest noble gas is Helium
Describe a chemical change that occurs in the human body.
A prominent chemical change in the human body is cellular respiration
Why do endothermic reactions feel cold to the touch?
Endothermic reactions feel cold to the touch because they absorb heat energy from their surroundings
How can you identify an exothermic reaction in a laboratory setting?
they release heat energy into their surroundings as the reaction occurs
What is sublimation?
The term for the transition from a solid state state directly to a bypassing the liquid state.
What element is commonly known as the 'king of chemicals'?
The element commonly known as the "king of chemicals" is sulfuric acid
What happens to the chemical bonds during a chemical change?
During a chemical change, the chemical bonds between atoms in the reactant molecules break apart, and the atoms rearrange to form new bonds
How can you identify an endothermic reaction in a laboratory setting?
To identify an endothermic reaction in a laboratory setting, monitor the temperature change of the reaction mixture using a thermometer
How can you identify an exothermic reaction in a laboratory setting
observing a noticeable increase in temperature within the reaction mixture
What is plasma?
The state of matter has neither a definite shape nor a definite volume and is made up of ionized particles
Name the element with the highest atomic number that occurs naturally
The element with the highest atomic number that occurs naturally is Uranium
What is the difference between a chemical change and a physical change?
physical change alters the appearance or state of a substance without changing its chemical composition, while a chemical change involves the formation of a new substance with different properties by rearranging atoms and breaking or forming chemical bonds
What is the difference between an endothermic reaction and an exothermic reaction?
An endothermic reaction absorbs energy from its surroundings, causing a decrease in temperature, while an exothermic reaction releases energy to its surroundings, causing an increase in temperature
In what phase change is heat released by a substance without lowering its temperature?
this occurs during a phase change called condensation