Chemical Reactions
color change, temp change, gas production and precipitate
What are the starting and ending substances in a chemical reaction?
reactants and products
What is kinetic energy and provide and example.
the energy of motion
At what temperature does water become a solid?
at 0 degrees celsius
Provide 2 examples of a compound
many
What is an insoluble solid formed after a chemical reaction?
precipitate
How do atoms combine to form new chemicals?
a covalent bond
Describe how atoms or molecules move with high and low amounts of molecular kinetic energy.
High = lots of vibrating and colliding
low = low vibrating and colliding
Why is ice different than solids for other substances?
Ice is less dense than liquid water and floats on top.
What is the chemical equation for water?
H2 + O2 = H2o
What is the minimum number of atoms in a molecule or compound?
What is potential energy and give examples of 2 types of potential energy.
gravitational, elastic, chemical, magnetic and electrical
What is the lightest element and why?
hydrogen it only has one electron and one proton
How is a covalent bond formed?
What is the difference between an endothermic and exothermic reaction?
Endothermic means cold products and exothermic means hot products
Provide 2 examples of a chemical that is a molecule but not a compound.
many
What is temperature?
temperature is the average molecular kinetic energy of atoms or molecules
What pH is neutral?
pH 7
After mixing 2 clear liquids an orange solid was produced. What is the term for this and why did it occur?
a precipitate was formed because a new product was formed that is solid and orange
Why are product endothermic or exothermic?
Endothermic the products need energy to form. Exothermic the products are releasing energy.
In plants what is the chemical equation for glucose and what cell structure uses glucose?
photosynthesis and the mitochondria
Describe how two substances with different temperatures reach equilibrium when mixed together.
The fast atoms collide with the slow atoms. This causes the fast atoms to slowdown and the slow atoms to speed up until all are at the same motion.
What pH range is acidic and what pH range is basic?
0-6 is acidic and 8-14 is basic
What are the amounts and types of energy that a ball halfway down a hill possesses?
50% KE and 50% PE