Which of the following is a physical change?
a) Adding acid to milk to form sour cream
b) Adding enzymes to milk to form cheese
c) Adding bacteria to heated milk to form yogurt
d) Adding sugar to milk to form sweetened milk
a) Adding acid to milk to form sour cream
b) Adding enzymes to milk to form cheese
c) Adding bacteria to heated milk to form yogurt
d) Adding sugar to milk to form sweetened milk