The half-life of bromine-74 is 25 min. How much of a 4.0 mg sample is still active after 75 min?
a. 0.50 mg
b. 1.0 mg
c. 2.0 mg
d. 0.25 mg
e. 4.0 mg

the theoretical yield of sodium chloride when 36.0 g Na reacts with 75.2 g Cl2  is 91.5g of NaCl.

Molar mass of Na= 22.99

Molar mass of Cl= 35.45

So we have 36/22.99 moles of sodium and 75.3/35.45 moles of chlorine which makes 1.566 moles of Sodium and 2.124 moles of Chlorine. To form sodium chloride, one atom of sodium reacts with one atom of chlorine, so 1.566 moles of sodium will react with 1.566 moles of chlorine. Excess chlorine is 2.124 - 1.566 moles or 0.558 moles. Therefore, all 1.566 moles or 36 grams of sodium will react with 1.566 times 35.45 grams of chlorine or 55.515 to produce 91.51 grams of NaCl.

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Generally speaking, an atom's size increases along a group and across the periodic table from right to left. Every atom is made up of a nucleus and maybe one or more electrons.

The nucleus is made up of one or more protons and several neutrons. Only the most common type of hydrogen is devoid of neutrons. Every substance solid, liquid, gas, and plasma—is made up of neutral or ionized atoms. an electric charge Having a negative charge, an electron is a particle. The negative charge is 1.602 10-19 coulomb in magnitude. A proton's mass is 1/1837 that of an electron. amount of electrons. Electrons are located in the area termed the electron cloud that surrounds the nucleus of an atom.

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Sewage discharge that enters surface waters contains a number of harmful organisms that may cause the spread of waterborne diseases.

Recreational or drinking water that has been contaminated with disease-causing organisms or pathogens is what causes waterborne sickness. It should be noted that many aquatic infections can also spread from person to person, by contact with animals or their surroundings, or by consuming tainted food or beverages.

Waterways are also contaminated by chemicals and heavy metals from industrial and municipal wastes. These pollutants, which are poisonous to aquatic life and frequently shorten an organism's life span and capacity for reproduction, move up the food chain as predators devour their prey.

Thus, Sewage discharge that enters surface waters contains a number of harmful organisms that may cause the spread of waterborne diseases.

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The formal name of the resulting molecule is a triacylglycerol, also known as a triglyceride. This molecule is formed when three molecules of fatty acids and one molecule of glycerol join together through a process called esterification.

A triacylglycerol, also known as a triglyceride, is a type of dietary fat molecule composed of three molecules of fatty acid joined to one molecule of glycerol. This molecule is formed through a process called esterification, which involves the reaction of a fatty acid with an alcohol, such as glycerol, to form an ester bond. This bond is what holds the molecules of fatty acid and glycerol together to form the triacylglycerol molecule. Triacylglycerols are an important source of energy for the body, and are a major component of many foods, such as oils, butter, and margarine. In addition, triacylglycerols are used in the body to store energy, and are used as a building block for other types of molecules, such as lipoprotein and cholesterol.

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The two questions were:

Generally, Wegener's theory of continental drift, which proposed that the Earth's continents have moved over time and are still moving, was not immediately accepted by the scientific community when it was first proposed in the early 20th century. There were several reasons for this, but two of the main questions that remained about Wegener's ideas were:

These questions and other issues with Wegener's theory kept most scientists from accepting it until the mid-20th century when the theory of plate tectonics was developed and provided a more complete and satisfactory explanation for the movement of the continents.

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Fluorine have 7 valence electrons. When it gains one electron, the its outer electronic configuration becomes similar to that of neon.

Fluorine is 9th element in periodic table. It have total 9 electrons of which 2 are inner electrons and 7 are valence electrons. Fluorine is a 17th group element and is highly electronegative.

According to octet rule, when elements gains 8 electron in its valence shell they become stable. Hence, fluorine need one more electron to acquire octet.

Neon is 10th element having 8 valence electrons. When Fluorine gain an electron. Its valence electron configuration becomes that of  the neon.

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Cobalt(II) iodide or cobaltous iodide are the inorganic compounds with the formula CoI2 and the hexahydrate CoI2(H2O)6.

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A single replacement reaction is one in which one element is replaced by another. The reaction in the balanced equation is Zn(s) + H2SO4(aq) ZnSO4(aq) + H2 (g).

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A single displacement reaction is one in which one element is replaced by another. The reaction in the balanced equation is Zn(s) + H2SO4(aq) ZnSO4(aq) + H2 (g). So, choice B is the right one.

When an element from a compound is replaced by another element from the reactant to create a product, the reaction is referred to as a single displacement reaction.

The replacement or substitution is determined by the activity series or reactivity. The weaker and less powerful element will be replaced by the one with greater strength.

The equation for the balanced single-displacement reaction is

H2SO4(aq) + Zn(s) ZnSO4(aq) + H2 (g)

Here, zinc replaces hydrogen because it is more reactive than hydrogen and creates zinc sulphate as a result.

The balanced equation is therefore option B: Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g).

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Potassium Chloride has the smallest ionic separation because it has a smaller ionic radius than the other compounds.

Potassium Chloride has an ionic radius of 181 pm, while the other compounds have ionic radii of 186 pm (Sodium Chloride), 230 pm (Magnesium Chloride), and 272 pm (Calcium Chloride).

The ionic radius of an atom is a measure of the size of its ion when it is part of an ionic compound, such as a salt. Ionic radius is typically measured in picometers (pm). Potassium Chloride (KCl) has an ionic radius of 181 pm, while Sodium Chloride (NaCl) has an ionic radius of 186 pm, Magnesium Chloride (MgCl2) has an ionic radius of 230 pm, and Calcium Chloride (CaCl2) has an ionic radius of 272 pm. Therefore, Potassium Chloride has the smallest ionic separation when compared to the other compounds.

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The polyatomic ion that carries a positive charge is the ammonium ion ( NH 4 + ) .

In general , Polyatomic ions are having important formulas, names, and charges that should be memorized. During formation of ammonium ion, these nitrogen atom helps to gains a positive charge when they loose lone pair of electrons. When ammonium ion carries a positive charge, then it is  known as ammonium cation.

Hence, when special type of ionic compound is embellished by ammonium nitrate (NH4NO3), that contains two polyatomic ions, NH4+ and NO3−. So the polyatomic ion is a charged and composed of several atoms bound together.

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The solubility of Mg(OH)2 in g/L in an aqueous solution buffered at pH = 8.60, we can use the Ksp expression for the compound and the relationship is 3.26*10^7 g/L..

Ksp (Mg(OH)2) = [Mg2+][OH-]^2 = 5.61 * 10^-12 M3

At pH = 8.60, the concentration of hydroxide ions can be calculated using the following equation:

pH = -log[OH-]

so [OH-] = 10^-8.60

We can then use the Ksp expression and the concentration of hydroxide ions to find the solubility of Mg(OH)2:

5.61 * 10^-12 = [Mg2+][OH-]^2

= Mg2+^2

= [Mg2+] (10^-17.2)

The solubility of Mg(OH)2 in molarity is [Mg2+] = Ksp/[OH-]^2

so [Mg2+] = 5.6110^-12 / (10^-17.2) = 5.6110^5 M

To convert the solubility from molarity to g/L, we can use the formula

g/L = molarity * molar mass

The molar mass of Mg(OH)2 = 58.32 g/mol

so the solubility of Mg(OH)2 in g/L is:

solubility = 5.61 * 10^5 * 58.32 = 3.26 * 10^7 g/L

So the solubility of Mg(OH)2 in an aqueous solution buffered at pH = 8.60 is approximately 3.26*10^7 g/L.

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Provider Information is not required (for secondary containers used in the workplace) on a hazardous material label.

The following components need to be on a label to be GHS compliant:

Identification of the product

warning or danger as a signal word

Risk pictograms

Advisory statements

Statements of caution

Provider Information (not required for secondary containers used in the workplace)

If the primary container fails, secondary containment acts as a backup barrier to prevent leaking into an exposed area. It is necessary to store all containers of hazardous waste and liquid hazardous materials in an appropriate secondary containment system. Systems for secondary containment may include

What information must be on labels for chemicals used at work?

The warning or signal phrase "Danger," "Warning" pictograms, "Hazmat" or "Precautionary" remarks, and "Product" and "Supplier" identification signs (supplier identification is not required for secondary containers used in the workplace)

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The Lewis structure for a carbon monosulfide (CS) molecule is attached in the attachment below.

Lewis  structures are also called as electron dot structures and can be drawn if the molecular formula of a compound is known. It provides information regarding the nature of bond and the position of atoms .

They are also capable of exhibiting the lone pair if any present in a molecule or compound.Lewis defined a base to be an electron pair donor and an acid to be an electron pair acceptor.

They are capable of reflecting electronic structure of elements and even the pairing of electrons . In the diagram, each dot represents an electron while a pair of dots represent a bond between the atoms.

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An organism with IsCAP+P+O+Z+Y+A+/F’I+ will have a normal functioning Lac operon is false. It will have negative dominant repressor.

The Lac operon include the genes that involved in the metabolism.  An organism with IsCAP+P+O+Z+Y+A+/F’I+ will have a normal functioning Lac operon is false. It will have negative dominant repressor. It will bind to operator in the presence of the lactose.  The gene expressed if only when the lactose will be present and the glucose is absent.

The DNA will be released by the repressor, that allow the operator freely. The RNA polymerase sent to through the operator to see the structural elements.

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Avogadro’s wide variety, the wide variety of gadgets in a single mole of any substance (described as its molecular weight in grams), is the same as 6.02214076 × 1023. The gadgets can be electrons, atoms, ions, or molecules, relying on the character of the substance and the individual of the reaction (if any).

Avogadro's Law

Avogadro's law states that an "equal volume of all gases at the same temperature and pressure contain the same number of molecules"

For example:-

18g of water = 1 mole = 6.022* 10²³ molecules of water

1.008g of hydrogen = 1 mole = 6.022 *10²³ atoms of hydrogen

96.06g of SO₄²- ion = 6.022*10²³ ions of SO₄²-.

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molar mass of Cu(OH)2 is 97.561 means 1 mole of Cu(OH)2 mass is 97.561

so 1gm of Cu(OH)2  have 1/97.561 moles

by unitary method no of moles in Cu(OH)2 is

9.2*1/97.561=0.094 mole

i hope it helps btw i am from india

The temperature at which a reaction becomes spontaneous can be estimated by using the Gibbs free energy equation is 314 K

Gibbs free energy equation:

ΔG = ΔH - TΔS

where ΔG is the change in Gibbs free energy, ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.

A spontaneous reaction occurs when ΔG is negative, which means that the free energy of the system is decreasing.

Given the information provided, we have:

ΔH = +55.3 kJ

ΔS = +175.7 J/K

We can use the equation above to find the temperature at which the reaction becomes spontaneous:

ΔG = ΔH - TΔS

Now we can solve for T:

T = ΔH/ΔS = 55.3 kJ / 175.7 J/K = 314 K

So the temperature at which the reaction becomes spontaneous is approximately 314 Kelvin or 40.85 Celsius.

It's important to note that this is only an estimation, and the actual temperature at which the reaction becomes spontaneous could be different due to other factors such as the pressure and concentration of the reactants and products.

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A mixture of cis- and trans-3-methyl-2-hexene is hydroxylated, as shown in the diagram below. The most common definition of hydroxylation in chemistry is a chemical process.

A hydroxyl group is added to an organic molecule as a result (OH).The degree of hydroxylation refers to how many OH groups are present in a given molecule (ii). the process of hydroxylation. A hydrocarbon utilised in organic chemistry is hexene, which has the chemical formula C6H12. A chemical with two carbon atoms joined by a double bond is known as an alkene, and the prefix "-ene" denotes its presence. The word "hex" comes from the fact that the molecule has six carbon atoms in it.

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A face-centered cubic (FCC) lattice has 8 corners, each corner having an atom, and 6 faces, each face having an atom.

Therefore, there are 8+6=14 atoms in the unit cell. Since the atoms at the corners are shared with other cells, each unit cell has 4 unique atoms.

The answer is D) 4 atoms per unit cell.

A face-centered cubic (FCC) lattice has 8 corners, each corner having an atom, and 6 faces, each face having an atom. Therefore, there are 14 atoms in the unit cell. Since the atoms at the corners are shared with other cells, each unit cell has 4 unique atoms, meaning a metal such with a face-centered cubic lattice will have 4 atom(s) per unit cell.

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Under acidic or basic circumstances, carboxylic acid (CA) derivatives can undergo nucleophilic acyl substitution. Therefore nucleophilic acyl substitution is most likely the starting CA derivative.

A reaction known as nucleophilic acyl substitution occurs when a nucleophile creates a new bond with an acyl group's carbonyl carbon while simultaneously rupturing the bond between the carbonyl carbon and a leaving group. Due to the fact that a bond is being formed and broken on the same carbon, this reaction is categorised as a substitution.

Anhydrides undergo nucleophilic acyl substitution and are cleaved into two molecules: A carboxylic acid and either an ester or amide, if the nucleophile is an alcohol, or an amine, respectively.

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The correct statements that describes microscope are as follows:

A microscope is an optical instrument used for observing small objects.

It is an instrument that can be used to observe small objects that cannot be seen with the unaided eye. The image of an object is magnified through at least one lens in the microscope. This lens bends light toward the eye and makes an object appear larger than it actually is.

Therefore, it can be said that options 1, 3 and 4 are the true descriptions of a microscope.

The options to the incomplete question are as follows:

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Some people with alcohol dependence report that just the smell of alcohol creates a powerful sense of well-being, increasing the desire to drink the alcohol because of The UCR to the UCS of alcohol is a sense of well-being, and the CS of alcohol is likely to eventually elicit the CR of a sense of well-being.

Without any prior conditioning, UCS automatically cause (UCR) a sense of well-being. Alcohol (UCS) causes the UCR.

The UCR (feeling of well-being) is likely to eventually be evoked by the smell of alcohol because it is frequently coupled with actual alcohol (UCS). The UCR to the UCS of alcohol is a sense of well-being, and the CS of alcohol is likely to eventually elicit the CR of a sense of well-being.

The conditioned response will be eliminated by repeatedly pairing the CS (alcohol smell) with the UCS (alcohol) (CR). As a result, extinction has occurred.

Your question is incomplete but most probably your full question was

Some people with alcohol dependence report that just the smell of alcohol creates a powerful sense of well-being, increasing the desire to drink the alcohol. Explain this reaction using a classical conditioning model, and describe one possible way to decrease the reaction. Use the following terms in your answer:

A. Unconditioned stimulus

B. Unconditioned response

D. Conditioned stimulus

E. Conditioned response

F. Extinction

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Due to the fact that no electrons were transported, this was not a redox reaction.

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The right answer is D. Due to the fact that no electrons were transferred, this was not a redox reaction.

By calculating the oxidation number of each atom on both sides of the arrow, we can determine whether a reaction is a redox reaction.

This is not a redox reaction because the oxidation number of any atom remains constant.

An oxidation-reduction reaction is any chemical process in which a molecule, atom, or ion experiences a change in its oxidation number as a result of gaining or losing an electron.

+2 +6 -2       +1     -2    +2 -2      +1      +6   -2

Cu   S  O4 + Na2  S → Cu  S   + Na2  S     O4

When oxidation and reduction occur simultaneously, this is known as a redox reaction. CuO+H2-Cu+H2O. In this process, for instance, copper oxide is reduced to copper, while hydrogen is oxidised to water.

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The Lewis acid in the reaction Pt²⁺(aq) + 4NH₃(aq) ⇌ Pt(NH₃)₄²⁺(aq) is Pt²⁺(aq).

A Lewis acid is defined as a chemical species that has an empty orbital that is able to accept a lone pair of electrons from a Lewis base to form a Lewis adduct.

Lewis acids are electron pair acceptors, whereas Lewis bases are electron pair donors. Examples of Lewis acids include metal cations, electron-deficient molecules such as boron trifluoride (BF3) and aluminum chloride (AlCl3), and certain types of organic molecules such as carbenes.

For the given reaction Pt²⁺(aq) + 4NH₃(aq) ⇌ Pt(NH₃)₄²⁺(aq), the Lewis acid is Pt²⁺ (aq).

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There are 30 protons, 30 electrons and 31 neutrons in a neutral atom of 30p (phosphorus-30).

Every atom is made up of a nucleus and one or more electrons that are attached to the nucleus. One or more protons and a number of neutrons make up the nucleus. Only the most prevalent kind of hydrogen is neutron-free. Every solid, liquid, gas, and plasma is made up of atoms that are either neutral or ionized. An atom is a matter particle that specifies a chemical element uniquely. An atom is made up of a central nucleus and one or more negatively charged electrons. The nucleus is positively charged and contains one or more protons and neutrons, which are relatively heavy particles.

Here,

A neutral atom of 30p has 30 protons, 30 electrons, and 31 neutrons (phosphorus-30).

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The toxic chemicals is different from the safe chemical because the stronger attraction between it's molecule than the safe chemical.it molecule now move away from each. The correct option is C

Toxic chemical can be defined as a substance that can be poisonous or cause health effects. Some examples of toxic chemical include ammonia, acid, bleach, chlorine, and carbon monoxide.

Therefore toxins are substances created by plants and animals that are poisonous to humans. Toxins may also include some medicines that are helpful in small doses but poisonous in large amounts.

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Considering the Charles's law, the volume of the gas at the higher temperature, assuming no change in pressure, is 5.39 L.

Charles' law establishes the relationship between the temperature and the volume of a gas when the pressure is constant: if the temperature increases, the volume of the gas increases, while if the temperature of the gas decreases, the volume decreases.

Mathematically, Charles's law states that the ratio between volume and temperature is constant:

V÷T= k

where:

V is the volume.

T is the temperature.

k is a constant

Being an initial state 1 and a final state 2, it is fulfilled:

V₁÷T₁= V₂÷T₂

You know:

Replacing in Charles's law:

2.50 L÷ 173 K= V₂÷ 373 K

Solving:

(2.50 L÷ 173 K)× 373 K= V₂

5.39 L= V₂

Finally, the final volume is 5.39 L.

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Answer:

non metal forms anions

metals for cations

nonmetals and metals bond because of electron transfer

an example is NaCl(Sodium chloride)

Answer:

molar mass of Cu(OH)2 is 97.561 means 1 mole of Cu(OH)2 mass is 97.561

so 1gm of Cu(OH)2  have 1/97.561 mole

by unitary method no of moles in Cu(OH)2 is

8.5*1/97.561=0.087 moles

1 mole of  Cu(OH)2 has 6.23*10^23 no of molecules of   Cu(OH)2

so 0.087 has 0.087*6*10^23=0.522*10^23 or 5.22*10^22(in scientific notation)

Explanation:i hope it helps btw i am from india