Physical and Chemical Changes
What is a physical change?
What is change in shape or size, state of matter change?
What is a chemical property?
What is
Can be observed through a reaction or the substance undergoing an irreversible change?
What does it mean to balance an equation?
What do subscripts in a chemical formula tell you?
What is the number of atoms of the element?
What is an exothermic reaction?
What is reaction that gives off or radiates heat?
Give an example of a chemical change.
What is one of the chemical changes?
What is a physical property?
What is
Can be observed and measured without changing the kind of matter being studied?
Balance the equation:
Al + HCl → AlCl3 + H2
What is:
2Al + 6HCl → 2AlCl3 + 3H2
How do coefficients affect a chemical equation?
What is may be changed in order to balance the equation /molecule/number count of each substance?
What is an endothermic reaction?
What is a reaction that absorbs or takes in heat?
How can you tell if a chemical change has occurred?
What is evidence of one of the chemical changes?
Unexpected color/temp
Formation of precipitate/gas
Name one physical property of water.
What is answers vary?
Why is it important to balance equations?
What is Abides by the law of conservation and gives you an accurate representation of what is created
How would you write the formula for 5 molecules of rust?
What is 5Fe2O3?
Give an example of an exothermic process.
What is combustion of fuels like wood, coal, or natural gas where heat is released into the surrounding environment as the fuel burns, water vapor turning to liquid?
What happens to the molecules in a substance during a physical change?
What is remain unchanged, stay the same?
Answer accepted if state speed up or slow down based on formation of gas/solid/liquid
Describe one chemical property of iron.
What is answers vary?
What is the balanced equation for
KClO3 → KClO4 + KCl
What is:
4KClO3 → 3KClO4 + KCl
What happens if you change a coefficient in a balanced equation?
What is you're only changing the number of molecules of that particular substance. However, when you change the subscripts, you are changing the substance itself?
Why is energy absorbed in an endothermic reaction?
Bonds/substances are being broken. Energy is needed to change forms or substances.
Explain the difference between a physical change and a chemical change.
What is chemical changes create something new and irreversible and physical are reversible and change state, shape or size?
How do chemical properties help identify substances?
What is chemical properties narrow down the list of substances that are able to react with known chemicals?
i.e. metals always rust
i.e. flammable materials always combust
What are the steps to balance a chemical equation?
What is First, count the atoms on each side. Second, change the coefficient of one of the substances. Third, count the numbers of atoms again and, from there, repeat steps two and three until you've balanced the equation.
What is the difference between subscripts and coefficients in a chemical formula?
What is The coefficient tells you how many molecules of that substance there is. The subscript tells you what the substance it?
Describe a real-life example of an endothermic reaction.
What is photosynthesis, evaporating liquids, melting ice, dry ice, alkane cracking, thermal decomposition, ammonium chloride in water, etc.?