I have no idea how to do this help plz!

Answer:

Free chlorine involves the amount of chlorine that's able to sanitize contaminants, while combined chlorine refers to chlorine that has combined directly with the contaminants. Total chlorine is basically the sum of free chlorine and combined chlorine.

Explanation:

chlorine -35 being chlorine

chlorine -37 being free chlorine

Answer:

Radiation

Explanation:

Answer:

The common application of indicators is the detection of end points of titrations. The colour of an indicator alters when the acidity or the oxidizing strength of the solution, or the concentration of a certain chemical species, reaches a critical range of values.

Answer: A. that do not participate in the reaction

Answer:

a

Explanation:

a p e x :)

Answer:

2.5 g mass of Ra-226 will remain after 4800 years.

Explanation:

Given data:

Mass of Ra-226 = 20 g

Sample remain after 4800 years = ?

Solution:

Half life of Ra-226 = 1600 years

Number of half lives passed = T elapsed / half life

Number of half lives passed = 4800 year / 1600 year

Number of half lives passed = 3

At time zero = 20 g

At first half life = 20 g/2 = 10 g

At 2nd half life = 10 g/2 = 5 g

At 3rd half life = 5 g/2 = 2.5 g

Thus, 2.5 g mass of Ra-226 will remain after 4800 years.

Answer: They are all odorless, colorless, monatomic gases with very low chemical reactivity.

Explanation: Plz give brainliest

Answer:

Explanation:

halogen group

Electron affinities are negative numbers because energy is released. The elements of the halogen group (Group 17) gain electrons most readily, as can be seen from their large negative electron affinitie

Answer:

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Explanation:

Answer:

Periodic tables can use color to identify other element characteristics. For example, an electronegativity periodic table color codes the elements based on how electronegative they are. The valence periodic table uses color to identify the most common valence state for each element.Oct 2, 2019

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The color given to a the elements in periodic table is to characteristics of the elements mainly to identify whether they are solid, gas or liquid. Thus option D is correct.

A periodic table contains all the discovered elements which are classified into different groups and periods. Groups are vertical columns of elements with similar properties and same number of valence electrons.

Periods are horizontal rows from left to right with an increase in atomic number. There are 18 groups and 7 periods in periodic table. Each group has given each color and some elements showing exceptional characteristics such as hydrogen and helium have separate colors.

All the first group elements called alkali metals have one color and the second groups elements with another color, All the d-block elements are given the same colour and metals in p-block elements have the same color.

Similarly, all the metalloids have one color and all other gases have the same colour in which inert gas group and halogen group have seperate colours.

Hence, the color in periodic table helps to identify the element's nature like its state also. Thus option D is correct.

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Answer:

If the reactants in the chemical reactions are known, then the products can be predicted because the pattern of the chemical reactions is being followed. The pattern for a single replacement is A + BC --> AC + B. This is like the Hear It Pop Chemical Reaction which is also an example of the single replacement.

Explanation:

Answer:

1.8069*10²⁴molecules of CO₂ and H₂O are produced.

Explanation:

C₃H₅OH + O₂ → CO₂ + H₂O

The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.

Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts

Left side: 3 C, 6 H and 3 O.

Right side: 1 C, 2 H and 3 O.

The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.

By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.  

So, balancing the C:

C₃H₅OH + O₂ → 3 CO₂ + H₂O

Then:

Left side: 3 C, 6 H and 3 O.

Right side: 3 C, 2 H and 7 O.

Now, balancing the H:

C₃H₅OH + O₂ → 3 CO₂ + 3 H₂O

Then:

Left side: 3 C, 6 H and 3 O.

Right side: 3 C, 6 H and 9 O.

Finally, balancing the O:

C₃H₅OH + 4 O₂ → 3 CO₂ + 3 H₂O

Then:

Left side: 3 C, 6 H and 9 O.

Right side: 3 C, 6 H and 9 O.

Since you have the same amount of each element on each side of the reaction, the reaction is balanced. Then 3 moles of CO₂ and 3 moles of H₂O are produced.

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole and it applies to any substance.

Then the following rule of three applies: if 1 mole contains 6.023*10²³ molecules, then 3 moles of CO₂ or 3 moles of H₂O, how many molecules does it contain?

[tex]amount of molecules=\frac{3 moles* 6.023*10^{23} molecules}{1 mole}[/tex]

amount of molecules= 1.8069*10²⁴

1.8069*10²⁴ molecules of CO₂ and H₂O are produced.

Answer:

i think it haven't impact because oxygen is very sensitive for our life and from plants there is so many kinds of food sources soo

Answer:

[tex]\huge\bf\underline{\underline{\pink{A}\orange{N}\red{S}\green{W}\purple{E}\blue{R}}}[/tex]

ONLY 20.95% IN THE AIR

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Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{9.20 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 15.282392..[/tex]

We have the final answer as

Hope this helps you

Answer:

Microwaves

Explanation:

Microwaves have more energy than blue light

Among microwaves or blue light, blue light has a higher frequency. This is because blue light belongs to the visible region has a short wavelength and produces a higher amount of energy.

The frequency of any wave is inversely related to the wavelength. This means that when the frequency of the wave increases, the wavelength decreases. While the relationship between frequency is directly related to the energy.

According to the context of this question, gamma rays have the highest frequency and shorter wavelength, while radiowaves have a shorter frequency and the highest wavelength.

Therefore, blue light has a higher frequency. This is because blue light belongs to the visible region has a short wavelength and produces a higher amount of energy.

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Answer:

reverse osmosis

Explanation:

Water treatment is often complicated because it deals with the chemical makeup of the water, which varies widely. The first step is to determine what contaminants should be removed. Unfortunately, this is not always a straightforward process. Many contaminants make themselves known in obvious ways, such as iron or hydrogen sulfide, which can cause taste and odor issues. Other contaminants, such as arsenic or pesticides, are only uncovered through a sophisticated laboratory analysis.

It is important to test the water so that the right type of treatment system can be selected. Keep in mind, however, that more than one analysis may be necessary to get a baseline because water quality fluctuates. More information on possible contaminants in a specific area can be obtained by talking to residents, the local health department, the water department, or the state geological society. In addition, your laboratory should be able to recommend appropriate tests based on a customer’s concerns and the information provided about the water source. It is important not only to address customers’ concerns but also to educate them about potential contaminants they may not have considered.

Answer:

35.50

Explanation:

There are two stable isotopes, 35Cl (75.77%) and 37Cl (24.23%), giving chlorine a standard atomic weight of 35.45

Mole measure the number of elementary entities of a given substance that are present in a given sample. To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol). Therefore option c is correct option.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance.

Mathematically,

Mole of Fe element=  mass of Fe element÷ Molar mass of Fe element

mass= Mole of Fe element ×Molar mass of Fe element

Substituting the given values in above formula we get

mass= 2.25 mol× 55.84 g/mole

mass= 2.25 mol× 55.84 g/mole

To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol).

Therefore option c is correct option.

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Answer:

[tex]Mass = 102g[/tex]

Explanation:

Given

Compound: [tex]Al_2O_3[/tex]

Required

Determine the equivalent mass

In the above compound, we have: 2 Al and 3 (O)

The atomic mass of Aluminium is:

[tex]Al = 27[/tex]

The atomic mass of Oxygen is:

[tex](O) = 16[/tex]

So, the equivalent mass is:

[tex]Mass = 2 * 27 + 3 * 16[/tex]

[tex]Mass = 54 + 48[/tex]

[tex]Mass = 102g[/tex]

Answer:

According to Bronsted-lowry concept  an acid is a hydrogen donnor and a base is a hydrogen acceptor.

Explanation:

Answer:

Conductivity of a substance is defined as 'the ability or power to conduct or transmit heat, electricity, or sound'.

Explanation:

hope it helps

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Answer:

i think it's will difference from compund to compund

19.4 mol Kr

Chemistry

Stoichiometry

Gas Laws

Math

Pre-Algebra

Order of Operations: BPEMDAS

Step 1: Define

435 L Kr at STP

Step 2: Identify Conversions

[STP]   22.4 L = 1 mol

Step 3: Convert

[tex]435 \ L \ Kr(\frac{1 \ mol \ Kr}{22.4 \ L \ Kr} )[/tex] = 19.4196 mol Kr

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

19.4196 mol Kr ≈ 19.4 mol Kr