Answer:
A. an equal and opposite reaction force
Explanation:
This means that there is a natural reaction of force
A forest fire is considered a chemical change because of the changing of the wood by combustion, which is not a physical change.
When multiplying and deviding follow the least number of sf.
since wavelength = 1/period
hence wavelength=1/2.7
=0.37 (2sf)
Answer:
7 cm
Explanation:
If the following digit is greater than or equal to 5, the decimal place is rounded up (moved up to the next number); if the following digit is less than 5, the decimal place stays the same.
4.6 + 2.35 = 6.95 cm
However, as stated in your question, cm is only being measured to the nearest 0.1 centimeters in your question.
So, you would round the digit 9 up by 1, meaning you would round it to 10. However, there are only nine digits available in our base-10 counting system, so you carry the value over,
6.95 cm could be rounded to '6. 100 cm', which is 7 cm.
Answer:
0.5 mol
Explanation:
Given data:
Number of atoms of He = 3.01 ×10²³
Number of moles = ?
Solution:
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.02 × 10²³ is called Avogadro number.
1 mole = 6.02 × 10²³ atoms
3.01 ×10²³ atoms × 1 mol / 6.02 × 10²³ atoms
0.5 mol
