0.0300 mol of a substance had a mass of 4.50g. The relative formula mass of the substance is

]The image shows groundwater zones.

11111nata11111 [884]

Answer:

C.) 3 is the correct answer

7 0

3 years ago

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The current scientific verdict on the phlogiston theory demonstrates which two of the following principles?

masha68 [24]

Answer:

The two valid principles are:

Scientific theories can be replaced by better theories.

An experiment can disprove a theory that scientists have accepted.

Explanation:

The scientific knwoledge is not inmutable; it may (and does) change with new discoveries.

In fact, scientific theories cannot be proved right, instead they are constantly tested to try to disprove them. This is what the principle that theories are falsiable means.

As long as a scientific theory is not disproved it remains valid, but new discoveries may lead, eventually, to its disprovement.

Scientific knowledge evolves because new procedures, new technologies, and new evidence leads to a better understanding and better explanations.

5 0

3 years ago

An alien civilization has different names and symbols for six elements. Place each element in the correct location in the period

Margarita [4]

Answer:

why whould I know that!!??

Explanation:

3 0

3 years ago

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Earth rotates once every 24 hours. What does this mean?

prohojiy [21]

B- Earth completes a full spin on its axis once every 24 hours.

6 0

3 years ago

Perform the calculation and record the answer with the correct number of significant figures.

kotykmax [81]

The question is incomplete, here is the complete question:

A. (6.5-6.10)/3.19

B. (34.123 + 9.60) / (98.7654 - 9.249)

Answer:

For A: The answer becomes 0.1

For B: The answer becomes 0.4884

Explanation:

Significant figures are defined as the figures present in a number that expresses the magnitude of a quantity to a specific degree of accuracy.

Rules for the identification of significant figures:

Digits from 1 to 9 are always significant and have infinite number of significant figures.
All non-zero numbers are always significant. For example: 664, 6.64 and 66.4 all have three significant figures.
All zeros between the integers are always significant. For example: 5018, 5.018 and 50.18 all have four significant figures.
All zeros preceding the first integers are never significant. For example: 0.00058 has two significant figures.
All zeros after the decimal point are always significant. For example: 2.500, 25.00 and 250.0 all have four significant figures.
All zeroes used solely for spacing the decimal point are not significant. For example: 10000 has one significant figure.

Rule applied for addition and subtraction:

The least precise number present after the decimal point determines the number of significant figures in the answer.

Rule applied for multiplication and division:

In case of multiplication and division, the number of significant digits is taken from the value which has least precise significant digits

For A: (6.5-6.10)/3.19

This a a problem of subtraction and division.

First, the subtraction is carried out.

$\Rightarow \frac{6.5-6.10}{3.19}=\frac{0.4}{3.19}$

Here, the least precise number after decimal was 1.

$\Rightarrow \frac{0.4}{3.19}=0.125$

Here, the least precise number of significant digit is 1. So, the answer becomes 0.1

For B: (34.123 + 9.60) / (98.7654 - 9.249)

This a a problem of subtraction, addition and division.

First, the subtraction and addition is carried out.

$\Rightarow \frac{34.123+9.60}{98.7654-9.249}=\frac{43.723}{89.5164}=\frac{43.72}{89.516}$

Here, the least precise number after decimal in addition are 2 and in subtraction are 3

$\Rightarrow \frac{43.72}{89.516}=0.48840$

Here, the least precise number of significant digit are 4. So, the answer becomes 0.4884

6 0

3 years ago