Given that work function for sodium metal is 1.82eV,,calculate the threshold frequency for sodium.​

Answer:

Concentric circles of contour lines indicate a hilltop; concentric circles with hachure marks indicate a close depression.

Explanation:

Hope this helped Mark BRAINLIEST!!!

Let's analyze each statement one by one.

1. Litmus green allows us to identify a base and an acid so it is correct.

2. Bases have a pH greater than 7 but for acids, their pH is lower, so 2 is not correct.

3. Strong acids and bases are able to release ions easily, this makes them conduct electricity easily. Correct.

4. Only acids will produce hydrogen gas when reacting with a metal. They will produce salt and H2. Not correct.

5. Only bases have a characteristic bitter taste. Acids have a sour taste. Not correct.

So, the properties would be possessed by BOTH acids AND bases will be: 1 and 3

Answer:

2.... is the answer..

Hope it helps!!!

Answer:

2 is the answer

Explanation:

Am correct

Answer:

See attached picture.

Explanation:

Hello,

In this case, given the compounds we notice:

a. Since carbon has four valence electrons (group IVA), it has three hydrogen atoms around it as well as a fluorine atom which has seven valence electrons (group VIIA). Moreover, we notice both carbon and fluorine attaining the octet.

b. In this case, two nitrogen atoms which have five valence electrons each (groupVA) are bonded via a single bond and two hydrogen atoms are bonded to each nitrogen atom in order to attain the octet for nitrogen only.

Thus, structures are given on the attached picture.

Regards.

Lewis structure for each covalent molecule CH₃F and N₂H₄ are attached to the image below.

a. CH₃F:

Carbon (C) has 4 valence electrons, Hydrogen (H) has 1 valence electron, and Fluorine (F) has 7 valence electrons.

The total number of valence electrons in CH3F can be calculated as follows:

1 carbon atom (C) × 4 valence electrons = 4 valence electrons

3 hydrogen atoms (H) × 1 valence electron = 3 valence electrons

1 fluorine atom (F) × 7 valence electrons = 7 valence electrons

Total valence electrons = 4 + 3 + 7 = 14

b. N₂H₄:

Nitrogen (N) has 5 valence electrons, and Hydrogen (H) has 1 valence electron.

The total number of valence electrons in N2H4 can be calculated as follows:

2 nitrogen atoms (N) × 5 valence electrons = 10 valence electrons

4 hydrogen atoms (H) × 1 valence electron = 4 valence electrons

Total valence electrons = 10 + 4 = 14

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Answer:

Bromohydrin and chlorohydrin are examples of halohydrins (where X = Br or Cl).

Answer:

eat this

Explanation:

The incorrect part of the chemical equation is the coefficient for the oxygen gas reactant.

        2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

        2 C2H10 (should be C2H6) + 10 O2 → 8 CO2 + 10 H2O

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The total number of electrons  Al+3. Fe¹3 Mg² Sn¹² Co²Co³ Lit¹ Cr+3,  Rb Pt+2 are 3, 3, 2, 12, 2, 3, 0, 3.0,2 electrons

Electrons are subatomic particles that have a negative charge and are found outside the nucleus of an atom. They orbit the nucleus in shells or energy levels and are involved in chemical bonding and electricity. Electrons are much smaller in size compared to protons and neutrons, which make up the nucleus of an atom.

Al+3 has 10 electrons (13 protons - 3 electrons).

Fe¹3 has 20 electrons (26 protons - 3 electrons).

Mg² has 10 electrons (12 protons - 2 electrons).

Sn¹² has 50 electrons (50 protons - 12 electrons).

Co² has 27 electrons (27 protons - 2 electrons).

Co³ has 26 electrons (27 protons - 3 electrons).

Li¹ has 3 electrons (3 protons - 0 electrons).

Cr+3 has 21 electrons (24 protons - 3 electrons).

Rb¹ has 37 electrons (37 protons - 0 electrons).

Pt+2 has 76 electrons (78 protons - 2 electrons).

Therefore,  The number of electrons in an atom determines its chemical behavior and the way it interacts with other atoms.

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Answer:

the material will be water and oxygen

Answer:

c seems like the best answer

Answer:

If n = 4, then the possible values of 1 and m depend on the equation or expression being used. Without more information, it is impossible to determine what the possible values of 1 and m might be. Can you please provide more context or information about the problem you are trying to solve?

Answer:

12

Explanation:

the 4 by the element symbol O multiplied by the 3 on the outside of the parentheses

Answer:

\(\boxed {\boxed {\sf C. \ 12 \ oxygen \ atoms }}\)

Explanation:

We are given the chemical formula:

\(Fe(ClO_4)_3\)

There are 3 elements here:

The question asks for the number of oxygen atoms, so we can just focus on the O in the formula.

The O has a subscript of 4, indicating there are 4 oxygen atoms in the compound. But the compound is also enclosed in parentheses with a subscript of 3. Therefore, there are 3 of the compounds with 4 oxygen atoms.

We can multiply 3 and 4.

There are 12 oxygen atoms.

Answer:

which property is least helpful in identifying a sample of matter is (B) VOLUME

Explanation:

volume depend on the amount of substance present and are not useful in the identification of a sample of matter. volume is an extensive property so it is not useful identifying the sample of matter.

Taking into account the definition of avogadro's number,  the correct answer is option D. 5.42×10²⁴ ions of Na⁺ are found in 3 moles of Na₃PO₄.

An ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions: the metal atom becomes a positive ion (called a cation) and the non-metallic atom becomes a negative ion (called an anion).

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. Avogadro's number applies to any substance.

In this case, you have 3 mol of Na₃PO₄.

Subscripts indicate the amount of moles of iones present in the ionic compound.

In this case, 1 mole of the compound has 3 moles of Na⁺ and 1 moleof PO₄³⁻. So, in 3 moles of Na₃PO₄ you have 9 moles of Na⁺ and 3 moles of PO₄³⁻.

Then you can apply the following rule of three, considering the Avogadro's Number: if 1 mole of of Na⁺ contains 6.023×10²³ ions, 9 moles of Na⁺ contains how many ions?

\(amount of ions of Na^{+} =\frac{9 moles x 6.023x10^{23}ions }{1 mole}\)

amount of ions of Na⁺= 5.42×10²⁴ ions

Finally, the correct answer is option D. 5.42×10²⁴ ions of Na⁺ are found in 3 moles of Na₃PO₄.

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The calculated formula masses to 133.5 amu, we find that the substance with a formula mass closest to 133.5 amu is (d) AlCl3. Therefore, the answer is option D.

To identify the substance with a formula mass of 133.5 amu, we need to calculate the formula mass of each given substance and compare it to 133.5 amu.

(a) MgCl2:

The formula mass of MgCl2 can be calculated by adding the atomic masses of magnesium (Mg) and chlorine (Cl).

Mg: atomic mass = 24.31 amu

Cl: atomic mass = 35.45 amu

Formula mass of MgCl2 = (24.31 amu) + 2(35.45 amu) = 95.21 amu

(b) SCl:

The formula mass of SCl can be calculated by adding the atomic masses of sulfur (S) and chlorine (Cl).

S: atomic mass = 32.07 amu

Cl: atomic mass = 35.45 amu

Formula mass of SCl = 32.07 amu + 35.45 amu = 67.52 amu

(c) BCl:

The formula mass of BCl can be calculated by adding the atomic mass of boron (B) and chlorine (Cl).

B: atomic mass = 10.81 amu

Cl: atomic mass = 35.45 amu

Formula mass of BCl = 10.81 amu + 35.45 amu = 46.26 amu

(d) AlCl3:

The formula mass of AlCl3 can be calculated by adding the atomic mass of aluminum (Al) and 3 times the atomic mass of chlorine (Cl).

Al: atomic mass = 26.98 amu

Cl: atomic mass = 35.45 amu

Formula mass of AlCl3 = 26.98 amu + 3(35.45 amu) = 133.78 amu. Option D

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Answer:I suppose it is mercury...

Explanation:

I don't say u must have to mark my ans as brainliest but if it has really helped u plz don't forget to thnk me...

Answer:

Strong Acid

Explanation:

Hope this helps! :)

Answer:.

Explanation: Matter must have Mass and Volume to be considered matter!

If It takes 60mL of 0.20M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (\(H_2CO_3\)), then the concentration of the carbonic acid is 0.24M

The reaction between NaOH solution and \(H_2CO_3\) is written below

\(2NaOH + H_2CO_3 \rightarrow Na_2CO_3 + 2H_2O\)

Volume of NaOH, \(V_B\) = 60 ml

Volume of \(H_2CO_3\), \(V_A=25 ml\)

Molarity of \(H_2CO_3\), \(C_A=?\)

Molarity of NaOH, \(C_B=0.20M\)

Number of moles of \(H_2CO_3\), \(n_A=1\)

Number of moles of NaOH, \(n_B=2\)

The mathematical equation for neutralization reaction is:

\(\frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B}\)

Substitute  \(C_B=0.2 M\),  \(n_A=1\),  \(n_B=2\),  \(V_B\) = 60ml, and  \(V_A=25 ml\) into the equation above in order to solve for \(C_A\)

\(\frac{C_A \times 25}{0.2 \times 60}=\frac{1}{2} \\\\50C_A=12\\\\C_B=\frac{12}{50} \\\\C_B=0.24M\)

Therefore, the concentration of the carbonic acid is 0.24M

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Answer:

0.119 moles

Explanation:

Given that,

Mass measured by Nurse Antonio is 7 grams of NaCl

To find,

The no of moles of NaCl

Solution,

The number of moles is given by

\(n=\dfrac{m}{M}\)

m is given mass

M is molar mass

For NaCl, molar mass is 23+35.5 = 58.5 grams

So,

\(n=\dfrac{7}{58.5}\\\\n=0.119\ \text{moles}\)

Therefore, there are 0.119 moles of NaCl.

The physical and chemical properties of seawater vary according to latitude, depth, nearness to land, and input of fresh water. The physical and chemical properties of seawater have a great effect on organisms, varying especially with the size of the creature. Marine organisms have evolved a wide variety of unique physiological and morphological features that allow them to live in the sea.

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In comparison to modern, highly accurate density meters or pycnometers, hydrometers are far less accurate and temperature.

Thus,  Although they require very large sample sizes, hydrometers are rather simple to operate. Usually, 300 to 500 ml per measurement are required. Hydrometers frequently require calibration off-site as well.

With measurements taken by eye, user error is a major issue, and temperature management is especially challenging. Inaccurately bringing and maintaining samples at temperature might take a long time, and once more, user perception of temperature levels is used to determine temperature levels.

Pycnometers and hydrometers have a further problem in that the findings of alcohol measurement are challenging to evaluate and record.

Thus, In comparison to modern, highly accurate density meters or pycnometers, hydrometers are far less accurate and temperature.

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Answer:

If the temperature increases the molecular movement as well, and if it increases the same it will happen with the molecular movement.

Pressure, volume and temperature are three factors that are closely related since they increase the temperature, the pressure usually decreases due to the dispersion of the molecules that can be generated, so the volume also increases.

If the temperature drops, the material becomes denser, its molecules do not collide with each other, their volume and pressure increases.

Explanation:

The pressure is related to the molecular density and the movement that these molecules have.

The movement is regulated by temperature, since if it increases, the friction and collision of the molecules also.

On the other hand, the higher the volume, the less pressure there will be on the molecules, since they are more dispersed among themselves.

(in the opposite case that the volume decreases, the pressure increases)

The stage that this most accurately describes while using the PCR is the initiation of DNA synthesis, also known as the denaturation stage.

In the denaturation stage of Polymerase Chain Reaction (PCR), the double-stranded DNA template is heated to a high temperature to separate the two complementary strands and create single-stranded DNA. The denaturation stage is the first step in the PCR cycle.

In this stage, the heat-stable DNA polymerase denatures the DNA and the primers anneal to the complementary single-stranded template. This marks the beginning of the extension stage, where the DNA polymerase synthesizes new complementary strands along the template DNA.

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Answer:

.

Explanation:

A light-year is how astronomers measure distance in space. It's defined by how far a beam of light travels in one year – a distance of six trillion miles. Think of it as the bigger, badder cousin of the inch, the mile, the kilometer, and the furlong.

The boiling point of benzene when the external pressure is 440 torr is 80.1 °C (176.2 °F).

What is benzene?

Benzene is an organic compound composed of six carbon atoms in a ring structure, with one hydrogen atom attached to each carbon atom. It is a highly flammable, colorless liquid with a sweet smell. Benzene is a natural component of crude oil and is one of the most important organic chemicals used in industry. It is used in the production of plastics, resins, synthetic fibers, rubber, pesticides, detergents, drugs, and dyes. It is also used as a solvent for fats, oils, waxes, resins, and inks. Benzene is classified as a carcinogen and its exposure can cause a variety of adverse health effects, including acute myelogenous leukemia, lymphomas, and other forms of cancer.

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