Exact numbers need not be measured. They can be counted. Conversion factors and countable units come under exact numbers. Measured quantities are measured using a device.
1) Number of microseconds in a week -Exact as it need not be measured. It can be estimated using the conversion factors between microseconds, seconds, minutes, hours, days and week.
2) Number of inches in a mile - Exact number as it is an established conversion factor.
3) The mass of a paper clip - Measured number as it has to measured using a weighing balance.
4) The number of pages in a book - Exact number as it is not measured. It can be counted.
5) Surface area of the dime-Measured number as it has to be measured.
6) The number of ounces in a pound-Exact number as it is a constant value.
Answer:
42) 76
b)70
Explanation:
52) because you don't want to confuse different units. one ex)1cm is 1/ 100 of a meter
55) 1 km=1,000 meters
b) 10 decimterers = 1 meter
56)The SI standard for length is the meter the standard for volume is the cubic decimeter
ex) 1cm³=1mL
57) The two scales are the same. but there are no negative temperatures in Kelvin. 0 Kelvin is the lowest temperature possible.
0 Kelvin= -274.5 Celsius
C
A has 2H 2O on the left and 4H 2O on the right
B has 4H 4O on the left and 4H 2O on the right
D has 2H 2O on the left and 2H 4O on the right
C has 2H 2O and 2H 2O so is balanced.
A polar bond is when the charge distribution between two atoms is unequal whereas in a polar molecule the charge distribution is not symmetric