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3 years ago

A chemical element is a pure substance that consists entirely of one type of what

1 answer:

3 0

A chemical element is a pure substance that consists entirely of one type of atom. Atoms of any element should have same number of protons but they can have different number of neutrons.

Elements are the simplest substances that can not be broken down by using the chemical reactions these can be changed into other elements using nuclear methods.

You might be interested in

Given the following balanced equation determine the amount of MgCl2 that can be produced from 65.0 grams of Mg. Mg + HCl -->

DedPeter [7]

Answer:

Mg + HCL --> MgCl2 + H2

mass 65.0 mass 257.26

RFM 24 RFM 95

moles 2.708 moles 2.708

Explanation:

mass of MgCl = 257.26 grams

4 0

3 years ago

I need help please, thanks!

oee [108]

Answer:

This question is somehow not clear, because a typical human eye can notice objects which have wavelengths from about 380 to 740 nanometers. This is called visible spectrum (the portion of the electromagnetic spectrum that is visible to the human eye). Electromagnetic radiation in this range of wavelengths is called visible light or simply light.

Someone even can see extra colors - they able to see beyond the visible spectrum. The reason that the human eye can see the spectrum is because those specific wavelengths stimulate the retina in the human eye. The human retina can only detect incident light that falls in waves from about 380 to 740 nanometers long, so we can’t see microwave or ultraviolet wavelengths. This also applies to infrared lights which has wavelengths longer than visible and shorter than microwaves, thus being invisible to the human eye.

In conclusion, the human eye can not notice that objects with wavelength not in the range of 380 to 740 nanometers.

Explanation:

5 0

3 years ago

The pyruvate dehydrogenase complex catalyzes the oxidative decarboxylation of pyruvate to form acetyl‑CoA. E1 , E2 , and E3 are

Mamont248 [21]

It’s B Thiamine puro pyrophosphate (TPP)

4 0

4 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

When 412.5 g of calcium carbonate react with 521.9 g of aluminum fluoride, how many

LekaFEV [45]

Answer
321.8 g CaF2
321.5 g Al2(CO3)3

5 0

3 years ago