Answer:
<span>The mole concept is important in chemistry because, "</span>Atoms and molecules are very small and the mole concept allows us to count atoms and molecules by weighing macroscopic amounts of material".
Explanation:
To understand this question lets take an example of Hydrogen atom. Let suppose you need to react Hydrogen with Oxygen. You need exactly Two Hydrogen atoms and one Oxygen atom to form one water molecule.
The mass of 1 hydrogen atom is 1.76 × 10⁻²⁴ grams. How will you count the Hydrogen atoms??? How can you measure exactly for 1 Million Hydrogen Atoms???
Answer to these questions and Calculations lies in Mole. It is found that 1 Mole of Hydrogen weights exactly 1.008 gram and contains 6.022 × 10²³ atoms. Now, having this reference in hand you can calculate for any number of Hydrogen atoms.
Result:
So the Mole helps us to zoom a microscopic level to a macroscopic level. :)
Answer is: variables that were manipulated during the experiment.
The two main variables in an experiment are the independent and dependent variable.
Dependent variable is the variable being tested and measured in a scientific experiment.
Dependent variables depend on the values of independent variables. The dependent variables represent the output or outcome whose variation is being studied.
Laboratory room number is the least important.
Answer:
Answers in explanation.
Explanation:
30. A (A chemical changes changes the chemical properties)
31. C (rusting is an example of a chemical change
32. B (A reaction requires energy, so some energy will be expelled)
33. B (Color change is an example of a chemical change)
34. A (The law of the conservation of mass: Mass and Energy cannot be created nor destroyed)
Answer:
modern cell theory
Explanation:
theory that cells are the basic structural, functional, and organizational units of both single-celled and multicellular organisms; cells divide and pass on hereditary information; and energy flows within cells.
I think it is B
Explained answer:
Glaciers dissolve and melt because they are made out of ice
