b. evaporation
c. filtration
d.sorting
SORTING METHOD can easily be used to separate a mixture of steel ball bearing and marbles. This separation method is suitable because the two substances that are mixed together have big sizes, so it is easy to separate the two by hand picking the particles. Sorting method is usually used as a separation technique when the size of the mixture is big and the mixed substances are in the same state.
Answer:
D. Sorting
Explanation:
Just tested
a. True
b. False
a) 8
40*20%
=40*20/100
=800/100
=8
The atomic weight of the unknown element, which is approximately 20% less than calcium (40 amu), is estimated to be 32 amu.
The atomic weight of an unknown element is said to be approximately 20% less than that of calcium, which has an atomic weight of 40 atomic mass units (amu). To calculate the approximate atomic weight of the unknown element, take 20% of 40 (which is 8) and subtract it from 40. The result is 32 amu (40 - 8 = 32), so the correct answer is (c) 32.
#SPJ11
b. 56.00 s ( a time measured by a stopwatch)
c. 4 choices ( the number of choices in this list)
d. 3 lbs ( the weight of an object measured on a scale )
Answer: a. 2.54 cm ( the number of centimeters in exactly 1 in) and c. 4 choices ( the number of choices in this list)
Justification:
1) a. 2.54 cm ( the number of centimeters in exactly 1 in)
Although the exact length of one inch has varied in the past, currently the inch is defined as exactly 2.54 cm, so this is an exact number.
b. 56.00 s ( a time measured by a stopwatch)
The time measured by a stopwatch is not an exact number. The number is limited by the precision of the instrument (the stopwatch) and it migh have been 56.004 instead of 56.00, and the stopwatch cannot shoe that. So, this is not an exact number.
c. 4 choices ( the number of choices in this list)
This is, indeed an exact number. It is 4, not 4.1, nor 3.9, nor any other number.
d. 3 lbs ( the weight of an object measured on a scale )
As reasoned with the stopwatch, this measure, 3 lbs, is subject to the precision of the scale. It is not an exact number. It could be other number close to 3: 2.99 for example.
These are exact numbers: c. 4 choices ( the number of choices in this list) and d. 3 lbs ( the weight of an object measured on a scale )
The exact number is a value that is known with complete certainty. Examples are counted numbers of objects or certain unit conversions such as exactly 3 feet in 1 yard. Another example is, a dozen is defined as 12 objects, and a pound is defined as 16 ounces.
Fraction an exact number is a fraction takes two integers and places them in a ratio, for example 3/4 or 10/15. A decimal can express the same numerical quantity, but it does so with a single number (like 0.75 or 0.66). So, the fraction makes the relationship among numbers clear in the way it is written.
While a decimal can express the same numerical quantity, but it does so with a single number (like 0.75 or 0.66).
a. 2.54 cm ( the number of centimeters in exactly 1 in) is decimal
b. 56.00 s ( a time measured by a stopwatch) is not exact numbers
c. 4 choices ( the number of choices in this list) is exact numbers
d. 3 lbs ( the weight of an object measured on a scale ) is exact numbers
Grade: 9
Subject: chemistry
Chapter: exact number
Keywords: exact number
b. 1s22s22p4
c. 1s22s22p5
d. 1s22s22p63s23p2
Your answer would be A.