Which of the following indicates that an endothermic reaction has occurred

Answer:

- 618.8 J.

Explanation:

Q = m.c.ΔT,

where, Q is the amount of heat released by steam (Q = ??? J).

m is the mass of the steam (m = 15.5 g).

c is the specific heat of the steam (c of steam = 1.996 J/g.°C).

ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 100.0°C - 120.0°C = - 20.0°C).

∴ Q = m.c.ΔT = (15.5 g)(1.996 J/g.°C)(- 20.0°C) = - 618.8 J.

Answer:

Gravity

Everything with mass has gravity

Answer:

Water cycle

Explanation:

The water from the ocean and sea evaporates into the atmosphere and goes into the sky to form clouds.

This turns the liquid water into water vapor in the atmosphere. Plants, too, help water get into the atmosphere through a process called transpiration! After absorbing water from the ground, plants “sweat” water vapor through their leaves to stay cool. Water can also get into the atmosphere from snow and ice.

An aerosol is a colloidal suspension in a gas, consisting of small particles or droplets that do not settle due to their small size. Examples include fog and smoke, where the dispersing medium is air. Understanding aerosols is important for their role in atmospheric processes and distinguishing them from other mixtures like solutions and suspensions.

An aerosol is a colloidal suspension in a gas. This means that an aerosol comprises tiny particles or droplets that are suspended within a gas. Unlike a suspension, where the particles can separate out over time due to their size (generally larger than 1 µm), the particles in a colloidal system, like an aerosol, do not settle because they are much smaller and range in size from about 2 to 500 nm. Aerosols can be composed of both solid and liquid particles dispersed in a gas, and these particles are stable enough not to settle quickly under the influence of gravity.

Examples of aerosols include fog, which consists of liquid water droplets dispersed in air, and smoke, which contains solid carbon particles also suspended in air. In both cases, the medium dispersing these particles is a gas (air), highlighting the defining characteristic of aerosols as a type of colloid. The significance of aerosols extends beyond simple examples, as they play integral roles in atmospheric processes, affecting weather, climate, and air quality, by influencing the scattering and absorption of radiation and serving as nuclei for cloud formation.

The ability of colloids, including aerosols, to scatter light, known as the Tyndall effect, further distinguishes them from solutions which are homogeneous mixtures and therefore do not exhibit this phenomenon. It's important to understand the distinction between aerosols and other types of mixtures, such as solutions and suspensions, to appreciate the unique physical and chemical behaviors of colloidal systems.

I believe it would be either the Density or the composition of its matter

It is the composition of matter

Answer: By pushing it.

Explanation: If you push the pendulum, the energy from your hand to the pendulum will be transferred thus giving the pendulum more energy.

Answer: It would be paint.

Explanation: it would be paint because it doesn't come completely together. another example of a heterogeneous mixture could be cereal and milk.

Answer:

V₂ = 0.483L = 483mL

Explanation:

Given parameters:

Inital volume of air in shampoo bottle V₁ = 553mL

Original temperature of the bottle T₁ = 65°C

Final temperature T₂= 22°C

Final volume of the gas in the bottle V₂=?

We first take the given units into standard units:

K = T°C + 273

For T₁ we have the temperature to be = 65 + 273 = 338K

                 T₂ = 22 + 273 = 295K

For the volume we convert to Litres or dm³

              1000mL = 1L

V₁ = 553 x 10⁻³L = 0.553L

Now apply one of the gas laws to solve this problem.

From Charles law, we know that the volume of fixed mass of gas is directly proportional to its absolute temperature if the pressure is constant.

Charles's law is expressed as:

                         [tex]\frac{V_{1} }{T_{1} }  = \frac{V_{2} }{T_{2} }[/tex]

The unkown in the equation is V₂ we the express it as the subject of the formula :

                    V₂ = [tex]\frac{V_{1} T_{2} }{T_{1} }[/tex]

Putting the parameters in the equation gives:

                   V₂ = [tex]\frac{0.553 x 295}{338}[/tex]

                  V₂ = 0.483L = 483mL

The Geiger Counter. Geiger counters are used to detect radioactive emissions, most commonly beta particles and gamma rays. The counter consists of a tube filled with an inert gas that becomes conductive of electricity when it is impacted by a high-energy particle.

Hope That Helps!!!

NOTE:Mark as BRAINLIEST!!!!!

Answer:

Geiger counters can detect all kinds of radiation, while scintillation counters can only detect ionizin radiation

Answer:

= 82%

Explanation:

Percentage purity is calculated by the formula;

% purity = (mass of pure chemical/total mass of sample) × 100

In this case;

1 mole of Ca(NO3)2 = 164 g

but; 164 g of Ca(NO3)2 = 40 g Ca

Therefore; mass of Ca(NO3)2 = 164 /40

                                                  = 4.1 g

Thus;

% purity of Ca(NO3)2 = (Mass of Ca(NO3)2/ mass of the sample)× 100

                                    = (4.1 g/ 5 g) × 100

                                    = 82%

To find the mass percent purity of calcium nitrate in the sample, calculate the equivalent mass of calcium nitrate from the given mass of calcium and then use this to determine the purity percentage, which comes out to be 81.82%.

The question asks for the mass percent purity of calcium nitrate in a sample that has been contaminated with silica. It is given that the sample has a total mass of 5.0 g and contains 1.0 g of calcium. Calcium nitrate (Ca(NO₃)₂) has a known molar mass of 164 g/mol. As calcium has a molar mass of 40.08 g/mol, and there is one mole of calcium in one mole of calcium nitrate, the mass of pure calcium nitrate can be calculated by converting the mass of calcium found in the sample to its equivalent mass in calcium nitrate.

First, find the number of moles of calcium in the sample:

moles of Ca = 1.0 g / 40.08 g/mol = 0.024945 moles

The moles of calcium nitrate are equal to the moles of calcium, as there is one calcium atom per molecule of calcium nitrate. Therefore, to find the mass of calcium nitrate:

mass of Ca(NO₃)₂ = 0.024945 moles × 164 g/mol = 4.091 g

The mass percent purity of calcium nitrate can then be calculated:

mass percent purity of Ca(NO₃)₂ = (mass of Ca(NO₃)₂ / total mass of sample) × 100 = (4.091 g / 5.0 g) × 100 = 81.82%

Answer:NF3 is the correct formula for nitrogen trifluoride.

Explanation:

In the given question, the correct formula for nitrogen trifluoride is [tex]\rm NF_3[/tex].

Nitrogen trifluoride is a covalent compound that is composed of one nitrogen atom and three fluorine atoms.

The nitrogen atom shares one of its valence electrons with each of the three fluorine atoms to form three single covalent bonds. The resulting molecule has a trigonal pyramidal shape, with the nitrogen atom at the center and the three fluorine atoms arranged around it.

The prefix "tri-" in the name of the compound indicates that there are three fluorine atoms in the molecule.

Therefore, [tex]\rm NF_3[/tex] is the correct formula for nitrogen trifluoride.

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Answer:

Explanation:

In a solubility table you find:

In a chemical equation the states of soluble compounds is identified as aqeous, using the letter "aq" in parenthesis, and the state of insoluble compounds is identified as solid, using "s" in parenthesis.

Then, the reaction showing the states of the reactants and products is:

In the chemical reaction AgNO3 + KCl = AgCl + KNO3, the state symbols for each compound are provided - AgNO3 (aq), KCl (aq), AgCl (s), and KNO3 (aq).

The state symbols for each compound in the reaction AgNO3 + KCl = AgCl + KNO3 are:

Hello There!

The moloques are moving faster in warm soda, so the carbonation leaves the soda faster.

Answer:

Same as what BlueFox stated above EXCEPT it is gas molecules move faster in warm soda

Explanation:

making fun of his typo,,,

The actual answer is size and temperature

All stars are very hot. They resemble a gigantic furnace of atomic energy. Some stars are much hotter than others and appear to be brighter. The brightness of a star also depends upon its size and its distance from the Earth. Larger stars tend to be brighter, but a star closer to the Earth will appear brighter than one the same size that is farther away.

PLEASE GIVE ME BRAINLIEST

Answer:

the correct answer is Size, Temperature, distance from the earth

hope this helps!! <33

132 pounds.  As you stated, their weight is 60 kg and 60 kg = 132.77 pounds

Answer:

The reaction will move to the left.

Explanation:

Ba(OH)₂ = Ba²⁺ + 2OH⁻,

Ba(OH)₂ is dissociated to Ba²⁺ and 2OH⁻.

H⁺ will combine with OH⁻ to form water.

So, the concentration of OH⁻ will decrease and the equilibrium is disturbed.

According to Le Châtelier's principle: when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.

The base will dissociate to form more OH⁻ and thus, the quantity of Ba(OH)₂ will decrease.

So, the right choice is: the reaction will move to the left, is the choice that will not happen to the equilibrium.

Final answer:

Adding H+ ions to a solution of Ba(OH)₂ shifts the equilibrium to the left, reducing the dissociation of Ba(OH)₂ and forming water by combining H₊ and OH₋ ions. The increase in H₊ leads to an increase in Ba(OH)₂ concentration as OH₋ ions are consumed.

Explanation:

When an acid is added to a solution of Ba(OH)₂, which is barium hydroxide, equilibrium dynamics according to Le Chatelier's principle tell us that the H₊ ions will react with OH₋ ions to form water. This reaction will cause the equilibrium of the solution to shift. Specifically, the ionization of Ba(OH)₂ which is represented by the reaction Ba(OH)₂ ⇒ Ba₂₊ + 2OH₋, will move towards the left to decrease the concentration of OH₋ ions that combine with incoming H₊ ions.

The reaction that will not happen is the dissociation of more Ba(OH)₂ to form additional OH₋ ions, because of the presence of excess H₊ ions that drive the equilibrium leftwards. The quantity of Ba(OH)₂ will increase at the expense of OH₋ ions, as they are consumed to form water.

Answer:

Explanation:

At constant pressure and temperature, the mole ratio of the gases is equal to their volume ratio (a consequence of Avogadro's law).

Hence, the complete combustion reaction that has a ratio of 100 ml of gaseous hydrocarbon to 300 ml of oxygen, is that whose mole ratio is 1 mol hydrocarbon : 3 mol of oxygen.

Then, you must write the balanced chemical equations for the complete combustion of the four hydrocarbons in the list of choices, and conclude which has such mole ratio (1 mol hydrocarbon : 3 mol oxygen).

A complete combustion reaction of a hydrocarbon is the reaction with oxygen that produces CO₂ and H₂O, along with the release of heat and light.

a. C₂H₄:

Precisely, for this reaction the mole ratio is 1 mol C₂H₄: 2 mol O₂, hence, this is the right choice.

The following analysis just shows that the other options are not right.

b. C₂H₂:

The mole ratio for this reaction is 2 mol C₂H₂ :5 mol O₂.

с. С₃Н₈

The mole ratio is 1 mol C₃H₈ : 5 mol O₂

d. C₂H₆

The mole ratio is 2 mol C₂H₆ : 7 mol O₂

Answer:

C. Scientists may study and discuss organisms easily

Answer:

the axis is tilted at 98 degrees

Explanation:

Uranus is blue, not green; it has an atmosphere of hydrogen and helium, not methane.  While it does have an icy cold temperature, that's not a very unusual characteristic for an outer planet.  However, the tilt of the axis is unusual; no other planet is tilted almost completely on its side!

Answer:

to make it more simple its A and D

Explanation:

edge

Arrhenius bases are the species that release hydroxide ions in the solution. Barium hydroxide and Caesium hydroxide are examples of Arrhenius bases.

Arrhenius bases are the chemical compounds that increase the concentration of the hydroxide ion in a solution when gets ionized. Whereas the acids release hydrogen ions when dissolved in water.

Barium hydroxide and Caesium hydroxide are the chemical species when dissolved in water will completely dissociate to release hydroxide ions and are the strong bases.

Therefore, option A. barium hydroxide and option D. cesium hydroxide are Arrhenius bases.

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Atoms that have different numbers of neutrons than protons and electrons are called isotopes.

Isotopes are atoms of the same element so they have the same number of protons. But, they have different mass numbers which means they have a different number of neutrons.

Out of the three you gave ecosystem is what I would call the most broad. An ecosystem includes living AND non-living things in an area

Community is all the LIVING things in an area (plants are included and I think bacteria is too, but I'm not sure)

Population is pretty narrow it just looks at specific species in one area. Population of mosquitoes doesn't include butterflies, if only looks at mosquitoes

Hope this helped!

Answer:

The sweetened tea mixture is called homogeneous.

The sweetened tea mixture is a homogeneous mixture unlike the heterogeneous mixture which has 2 phases.

Heterogeneous mixtures is defined as a type of mixture where  the composition is not uniform throughout the mixture.It consists as two or more phases. The phases are chemically distinct  and separate from each other.

As there are two or more phases present in heterogeneous mixtures they can be separated by solvent extraction  method where in one phase is miscible with the solvent while the other phase is immiscible.

Components of a heterogeneous mixtures are distinctly visible . There are two types of heterogeneous mixtures, the colloids and the suspensions.These two differ with each other with respect to particle size.It consists of 2 or more phases.

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Answer:

A negatron emission

Explanation:

We know that radioactivity orginates from instability of the nucleus. When the nucleus is unstable, radioactive emissions are produced in the form of any of these rays:

> Alpha particle emisson

>Beta particles

> Gamma rays

These emissions create a balance for a radioactive decay.

In balancing nuclear reactions we make sure that the charges on both sides must be conserved and that the mass number and atomic numbers conserved too. This means that the sum of mass number and atomic numbers on both side of the reaction must be equal.

The nucleons are the protons and neutrons, they add up to give the mass number. The atomic number is the proton number.

For the given radioactive reaction:

²³¹₉₀Th → ²³¹₉₁Pa + ?

From this equation, we see that the mass number is conserved but the atomic number is not.

The mass number is the superscript whereas the atomic number is the subscript.

Let's say the decay produces an emission of a particle denoted by X

²³¹₉₀Th → ²³¹₉₁Pa + ᵃₙX

What would the nature of X be?

For the charges and masses to be conserved, X must have mass number of 0 and an atomic number of -1.

Checking:

Mass number:

231 = 231 + a ( a is the mass number)

a = 231 - 231 = 0

Atomic number:

90 = 91 + n

n = 90- 91 = - 1

With X having a mass number of 0 and an atomic number of -1, we have a beta particle emission. Specifically, a negatron has been emitted.

A negatron is denoted as ⁰₋₁β which perfectly makes the equation conserved and suits the description of X.

The complete equation is thus written as:

²³¹₉₀Th → ²³¹₉₁Pa + ⁰₋₁β + energy

In the decay of thorium-231 to protactinium-231, a neutron inside the thorium nucleus converts to a proton, resulting in the emission of a beta particle to conserve charge and nucleon number.

The decay of the element thorium-231 (231/90Th) to protactinium-231 (231/91Pa) involves the emission of a decay particle. According to the laws of conservation of charge and nucleon number, we can determine the type of decay and the particle emitted by examining the change in atomic and mass numbers.

231/90Th decays to 231/91Pa which indicates that the mass number has not changed (indicating the total number of protons and neutrons remains constant) but the atomic number has increased by one. This suggests that a neutron has transformed into a proton and the particle emitted must account for the negative charge to conserve the total charge. Since a neutron (n) converting to a proton (p) emits a beta-minus particle ({{e}}) (an electron), which has a negative charge, the decay particle is therefore identified as a beta particle.

Answer:-

Try this formula:

W= Fd

F = W by d

Explanation:-

(Note: A newton-meter is the same thing as a joule, so the units for work are the same as those for energy – joules).

The force required to lift a rock at a vertical distance of 8 m if 80 j of work were done is 10 N.

A force is an effect that can alter an object's motion. Due to force, an object with mass can change its velocity, or accelerate.

Given,

Distance is 8 m

work done is 80 j

Now by the formula of work

[tex]\bold{Work = force \times distance}[/tex]

[tex]80= F\times 8\\\\F= \dfrac{80}{8} = 10 N[/tex]

Thus, the force required is 10 N.

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Explanation:

Metals are the substances or elements that contain more number of electrons.

Some of the properties of metals are as follows.

Acetone may be rinsed over materials to wash off explosive residue.

The real solution to the residue issue is to use methods that actually rinse away cleaner.

Some solvents and steam vapor systems are examples of residue-free chemistry. Completely water soluble and rinseable, soap-free products for carpet and hard floor care are a valuable part of the professional cleaner’s arsenal of residue-free cleaners.

In clean areas, all exposed surfaces should be smooth, impervious and unbroken in order to minimize the shedding or accumulation of particles or microorganisms and to permit the repeated application of cleaning agents, and disinfectants where used.

Acetone may be rinsed over materials to wash off the explosive residue. This can then be analyzed by x-ray techniques. Advance in explosives that has been proposed. Use of small color chips. These chips would be added to explosive materials available to the public.

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A thermodynamic quantity equivalent to the total heat content of a system

Answer:

a thermodynamic quantity to the total heat content of a system. it is equal to the internal energy of the system plus the product of pressure and volume. it is associated with a particular chemical process

Explanation:

i just looked up the definition.

Answer:

1. The limiting reactant is H₂O.

2. The theoretical yield of Al₂O₃ = 978.8 g.

Explanation:

1. Which is the limiting reactant?

2Al + 3H₂O → Al₂O₃ + 3H₂,

It is clear that 2.0 moles of Al react with 3.0 moles of H₂O to produce 1.0 moles of Al₂O₃ and 3.0 mole of H₂.

∴ 4.8 mol of Al (the remaining 1.7 mol is in excess) reacts completely with 7.2 mol of H₂O with (2: 3) molar ratio.

the limiting reactant is H₂O and the excess reactant is Al.

2. Calculate the theoretical yield.

Using cross multiplication:

2.0 moles of Al produce → 1.0 moles of Al₂O₃.

4.8 moles of Al produce → ??? moles of Al₂O₃.

∴ The no. of moles of Al₂O₃ produced = (1.0 mol)(4.8 mol)/(2.0 mol) = 9.6 mol.

∴ The theoretical yield of Al₂O₃ = (no. of moles)(molar mass) = (9.6 mol)(101.96 g/mol) = 978.8 g.

About 45.6 gAL are need to completely react with 135g FE2O3

To determine the mass of Al needed to react with 135 grams of Fe₂O₃, convert the mass of Fe₂O₃ to moles, use the stoichiometric ratio to find moles of Al needed, and then convert those moles to grams of Al to three significant figures.

The question is asking how many grams of aluminum (Al) are needed to completely react with 135 grams of iron(III) oxide (Fe2O3). This is a stoichiometry problem that requires using the balanced chemical equation:

Fe₂O₃(s) + 2Al(s) →2Fe(s) + Al₂O₃(s)

We start by converting the mass of Fe₂O₃ to moles using its molar mass:

1.0g Fe₂O₃ / 159.7 g/mol = moles of Fe₂O₃

Then we use the mole ratio from the balanced equation to convert from moles of Fe₂O₃ to moles of Al. The molar mass of Al is 27.0 g/mol. Finally, we convert moles of Al to grams using its molar mass to find the mass of Al needed for the reaction.

With the provided mass of 135g of Fe₂O₃, and the reaction stoichiometry, we can determine the mass of Al required which will be expressed to three significant figures.