Answer:
0.171 grams of oxygen combined with the metal.
Explanation:

Mass of magnesium oxide produced = 0.421 g
Mass of magnesium metal used = 0.250 g
Suppose reaction completely converts the magnesium into magnesium oxide.
Mass of oxygen combined with magnesium = m
0.421 g = 0.250 g + m
m = 0.421 g - 0.250 g = 0.171 g
0.171 grams of oxygen combined with the metal.
Scientific investigations that involve some kind of testing will make use of observations. Generally speaking, making observations is the first step of the scientific method. Based on those observations, a question is asked, and then a hypothesis and prediction will be stated. A scientist will set up a test, observe the outcome, and collect data on the test. That will lead the scientist to some kind of conclusion relating to the initial question and hypothesis....
Answer:
the action or power of focusing one's attention or mental effort.
Explanation:
42metres / 6metres which means it takes 7 seconds to run 42 metres
Answer:
the answer is: 1'699.98 ok i hope i have helped maybe