what are the normal freezing points and boiling points of the following solutions: (a) 21.2 g nacl in 135 ml of water and (b) 15.4 g of urea in 66.7 ml of water?

Answer:

Time taken 172.8 years

Explanation:

Given data:

Total amount of strontium-90 = 1000.0 g

Amount left = 15.625 g

Half life of strontium = 28.8 years

Time taken = ?

Solution:

Number of half lives:

At time zero = 1000.0 g

At first half life = 1000.0g/2 = 500 g

At second half life = 500 g/2 = 250 g

At third half life = 250 g/ 2 = 125 g

At 4th half life = 125 g/ 2= 62.5 g

At 5th half life = 62.5 g/2 = 31.25 g

At 6th half life = 31.25 g / 2 = 15.625 g

Time taken:

Time taken = number of half lives × half life

Time taken = 6×28.8 years

Time taken = 172.8 years

Explanation:

Sometimes it is necessary to put forth new theories to explain experimental results, Explanation:

Creativity is important to science because sometimes, it is necessary to put forth new theories to explain experimental results. Theories are explanation of scientific observations.

Answer: Without creativity, it would be difficult to come up with new methods to answer scientific questions, meaning we likely wouldn't learn anything new.​

Explanation: took the quiz

When you walk over a sidewalk with barefoot, your feet make contact with the surface, which conducts heat to your feet.Convection drives the majority of heat energy in the atmosphere.

Conduction transfers heat from heated sand to a bottoms of your feet.Heat is transferred by conduction when two items come into contact.Heat energy passes from the warmer to the colder of two materials when their temperatures differ.

conduction Three methods exist for transferring heat: conduction, convection, and radiation.Energy is transferred directly from one atom to another through conduction.

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The statement that is not correct is option (a), which claims that the density of a gas is typically much larger than the density of a solid or liquid.

In reality, the density of a gas is much lower than the density of a solid or liquid. This is because gases have much more space between their particles, and they move around freely, unlike solids and liquids, whose particles are packed more tightly together. When the temperature of a gas is changed, its volume changes more than the volume of a solid or liquid.

Similarly, when the pressure of a gas is changed, its volume changes more than the volume of a solid or liquid. And unlike solids and liquids, gases can expand to occupy the entire volume of their container.

Hence,the answer is A.

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Answer: v=d−at

Explanation: I don't know if this will help

Answer:

\(d = v + at \\ d - at = v \: \: or \: \: v = d - at\)

Answer:

The energy output objects that work with solar panels include solar inverters, charge controllers, batteries, and electric grid systems.

Explanation:

Answer: Energy of motion :)

Answer: the answer to your question is the energy of motion

Explanation:

Answer:

Explanation:

The table below indicates the “Molecular Geometry” of the central atom depending on whether the groups of electrons around it are covalent bonds to other atoms or simply lone pairs of electrons.

Answer:

b is your answer...........

Answer:

Limiting reactant is FeCl3; 1.7 g of Mg remain.

Explanation:

From the question;

The equation is;

3Mg(s) + 2FeCl₃(s) → 3MgCl₂(s) + 2Fe(s)

Amount of Mg = 41 g/24.31 g/mol = 1.687 moles

The limiting reactant yields the least amount of MgCl2

3 moles of Mg yields 3 moles of MgCl2

Hence 1.687 moles of Mg yields yields 1.687 moles of MgCl2

FeCl₃ = 175 g/162.2 g/mol = 1.0789 moles

2 moles of FeCl3 yields 3 moles of MgCl2

1.0789  moles of FeCl3 yields 1.0789  * 3/2 = 1.61835 moles of MgCl2

Hence FeCl3 is the limiting reactant

3 moles of Mg reacts with 2 moles of FeCl3

x moles of Mg reacts with 1.0789  of FeCl3

x = 3 * 1.0789  /2 = 1.61835 moles of Mg

Mass of Mg reacted = 1.61835 moles * 24.31 = 39.342 g

Mass of excess Mg = 41 g - 39.342 g = 1.7 g

Jake having recently purchased a new computer, jake will invest in Anti-spyware software  that will protect his computer from data corruption, pop-up ads, hackers, identity theft, and other online-related threats.

Anti-spyware is a type of software used to find and get rid of unwanted spyware programs. A form of malware known as spyware is placed on a computer without the user's knowledge in order to collect information about them. Although there may be a security risk for the user as a result, spyware more frequently reduces system speed by using processing power, installing software, or redirecting users' browser activity.

Anti-spyware software identify spyware through definition files that have been downloaded or through rule-based detection methods. Anti-spyware software can be used to find and remove spyware that has already been downloaded and placed on the user's computer, or it can function similarly to an anti-virus application by providing real security and preventing spyware from ever being downloaded.

So, Jake will spend money on anti-spyware software to protect his computer against malware such as hackers, pop-up advertising, data loss, and identity theft.

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Answer:

1. The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart.

2. The attractive intermolecular forces between particles that tend to draw the particles together.

Answer:

4. I think that they started with water that was the same tsmpurature because if they didnt start with the same temp of water then it would be harder to tell which one was better. and could hold the most heat.

5. yes i think it would matter, because if you have more water in one cup it might stay warmer than it would with the cups with less water, and if it was thicker it would hold mor heat because it is not so thin that the heat is just gonna come out it has to come through more for the heat to get out.

Explanation:

sorry if these are to long but thats how i would answer them.

hope it helped

Answer:

i think its the first one

Explanation:

im new to chemistry as while but im not completely sure.

The distance of a soccer player who runs the length of the pitch (20m) and then returns to the middle is 30m.

Distance and displacement are two quantities that seem to mean the same but are distinctly different with different meanings and definitions. Distance is the measure of “how much ground an object has covered during its motion” while displacement refers to the measure of “how far out of place is an object.” In this article, let us understand the difference between distance and displacement.

Distance is the total movement of an object without any regard to direction. We can define distance as to how much ground an object has covered despite its starting or ending point.

In the question, The length of full pitch is 20m. So to cover full  pitch one time the distance would be 20m and then the half pitch, the distance would be 10m. Total distance would be 30m.

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Answer:

-867.7

Explanation:

The volume in liters of a 1.0 mol/L aluminum chloride solution that contains 175. g of aluminum chloride (AICI3). is 0.93 L.

calculation:-

mass of AlCl3 = 175 g

moles of AlCl3 = mass / molar mass

= 175 g / 133.34 g/mol

= 0.938 mol

and we have a concentration of the solution

molarity = moles/volume (liter)

volume = 0.938 mol / 1.0 mol/L

= 0.93 L

Aluminum chloride is widely used in the production of rubber lubricants wood preservatives and paints. Used in pesticides and pharmaceuticals. As a flux when melting aluminum. Used as an antiperspirant. Aluminum chloride is corrosive and irritating to eyes skin and mucous membranes. May be harmful if swallowed.

Consuming large amounts can lead to phosphate deficiency. In human skin irritation studies, intermittent exposure of 6 days or more was given a mild rating. Aluminum chloride hexahydrate is an antiperspirant that acts on sweat cells. Topical aluminum chloride hexahydrate is used to treat excessive sweating also called hyperhidrosis.

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Answer:

It will go off.

Explanation:

Since the two bulbs are connected in series with the battery, when one bulb breaks breaks the circuit hence flow of current is stopped from moving to the other bulb

1. La tendencia general de la electronegatividad durante un período es que la electronegatividad aumenta durante un período

La opción correcta es a. Incremento

Razón

El número de electrones de valencia aumenta durante un período, por lo

que aumentar la tendencia del átomo a lograr la estructura de octeto

estable requiriendo atraer (cada vez menos a medida que avanzamos por

el período desde la izquierda a la derecha) compartieron electrones

cuando se forman enlaces, lo que  aumenta electronegatividad

2. El orden de electronegatividad creciente es Li → Ca → C → Se

Razón

La electronegatividad aumenta a lo largo del período y disminuye en el grupo.

Las ubicaciones de los elementos dados son;

Primero escribimos los elementos con los números de grupo más altos,

que son Se y C, después de lo cual tenemos Ca, luego Li, por lo tanto, en

orden creciente, obtenemos;

Li → Ca → C → Se

3. La opción correcta es d. N (nitrógeno)

Razón

El potencial de ionización representa la energía necesaria para eliminar un electrón de un átomo.

El potencial de ionización disminuye en un grupo y aumenta a lo largo de un período de izquierda a derecha.

Tenemos;

Por lo tanto, el elemento con mayor potencial de ionización es aquel que se encuentra en la posición más alta en el grupo 15 entre los elementos dados, que es el nitrógeno, N

4. La opción correcta para la definición de electronegatividad es la opción (a);

un. Es la tendencia relativa de un elemento a atraer electrones hacia sí mismo.

Razón

La electronegatividad es la capacidad relativa de un elemento dado para atraer electrones compartidos hacia sí mismo.

Por lo tanto, la opción correcta es a. es la tendencia relativa de un elemento a atraer electrones hacia sí mismo

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Answer:

2

Explanation:

in terms of cells, it exists from previous existing cells, that means scientist are built up by the work of other scientist

Answer:

the answer is B

Explanation:

Answer:

0.067M H3PO4

Explanation:

H3PO4 reacts with NaOH as follows:

H3PO4 + 3NaOH → 3H2O + Na3PO4

Where 1 mole of H3PO4 reacts with 3 moles of NaOH

To solve trhis question we need to find the moles of NaOH required. With the chemical equation we can find the moles of H3PO4 and its concentration as follows:

Moles NaOH:

50.0mL = 0.0500L * (0.20moles /L) = 0.0100 moles NaOH

Moles H3PO4:

0.0100 moles NaOH * (1mol H3PO4 / 3mol NaOH) = 0.00333 moles H3PO4

Concentration:

0.00333 moles H3PO4 / 0.0500L = 0.067M H3PO4

Answer:

A

Explanation:

Natural gas is flammable. A natural gas leak in a house can cause potential fires, and inhaling the gas can cause natural gas poisoning.

* Answer B: The fact that scientists have developed new ways of extracting natural gas - is an advantage, not a disadvantage.

* Answer C is wrong, because compared with some other fossil fuels, natural gas emits the least amount of carbon dioxide into the air when combusted -- making natural gas the cleanest burning fossil fuel of all.

* Answer D: the content of the statement is about the production process, not about using of natural gas.

....

Hope this answer can help you. Have a nice day!

Answer:

Explanation:D Extraction through fracking can contaminate groundwater

The horizontal component of velocity is constant throughout the motion. The distance traveled by the projectile is given by the equation d = V^2 sin2θ/g where d is the distance traveled.

Carl Lewis at the 1992 Olympics in Barcelona, Spain, won gold medals for the long jump (28 feet 5.5 inches).

This resulted from an initial velocity of 9.5 m/s at an angle of 40 degrees to the horizontal.Initial velocity is the initial speed and direction of a moving object at a particular instant in time.

Its direction is typically measured in degrees, with 0 degrees being to the right, 90 degrees being up, and 180 degrees being to the left. The horizontal is the axis that runs from left to right.

The angle between the horizontal and the initial velocity vector is referred to as the angle of projection. This is usually referred to as the theta symbol.

The vertical component of velocity is equal to the initial velocity multiplied by the sine of the angle of projection. This is due to the fact that velocity can be broken down into horizontal and vertical components.

The horizontal velocity is constant throughout the motion and the vertical velocity changes due to gravity.

Therefore, the vertical component of velocity is zero at the top of the motion and maximum at the bottom.

The maximum height reached by the projectile is given by the equation h = V^2 sin^2θ/2g where h is the maximum height, V is the initial velocity, θ is the angle of projection, and g is the acceleration due to gravity.

On the other hand, the horizontal component of velocity is equal to the initial velocity multiplied by the cosine of the angle of projection.

This is due to the fact that velocity can be broken down into horizontal and vertical components.

The horizontal velocity is constant throughout the motion and the vertical velocity changes due to gravity.

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Answer:

Chemical Family means a group of elements in the Periodic Table or, more commonly, compounds that share certain physical and chemical characteristics and have a common name.

A period in the periodic table is a row of chemical elements.

metalloid is an element (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid nonmetals or semiconductors.

1) write balanced chemical equation.

\(K_{2}CO_{3}_{(aq)}+2\ HBr_{(aq)}\ ->\ 2\ KBr_{(aq)}+CO_{2}_{(g)}+H_{2}O_{(l)}\)

2) separate into ions, if possible.

\(2\ K^{1+}_{(aq)}+CO_{3}^{2-}_{(aq)}+2\ H^{1+}_{(aq)}+2\ Br^{1-}_{(aq)}\ ->\ 2\ K^{1+}_{(aq)}+2\ Br^{1-}_{(aq)}+CO_{2}_{(g)}+H_{2}O_{(l)}\)

3) remove spectator ions.

\(2\ H^{1+}_{(aq)}+CO_{3}^{2-}_{(aq)}\ ->\ CO_{2}_{(g)}+H_{2}O_{(l)}\)

The net ionic reaction is that in which positive ions and negative ions of reactant and product are equal, resultant charge will be neutral.

2K⁺ +CO3²⁻ + 2H⁺ +2Br⁻ --> 2K⁺+ 2Br⁻ + CO2 + +H2O

The net ionic equation is the chemical equation that shows only those elements, compounds, and ions that are directly involved in the chemical reaction.

Example: - "NaOH" is "Na+ + OH⁻".

K₂CO₃(aq) + 2HBr(aq) --> 2KBr(aq) + CO₂ (g)+ H₂O(l)

Similarly, above reaction can be written as.

2K⁺ +CO3²⁻ + 2H⁺ +2Br⁻ --> 2K⁺+ 2Br⁻ + CO₂ + H₂O

Thus, above reaction is know as net ionic reaction.

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In general, foods high in saturated fatty acids are found in milk and meat food groups (Option B).

Saturated fats are those that are solid at room temperature and have no double bonds between their carbon atoms. Saturated fats are commonly found in foods of animal origin, such as fatty beef, pork, and poultry, as well as in butter, cheese, and other dairy products.

Lipids that are solid at ambient temperature are known as saturated fatty acids. They are present in meat and dairy products, including cheese, milk, and butter, as well as some plants, including coconut oil, cocoa butter, and palm oil. Foods high in saturated fats are usually of animal origin and are linked to an increased risk of heart disease.

Thus, the correct option is B.

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Dish of Cabbage, carrot, pea, cauliflower and brinjal are the meals we could enjoy that contain only plant products.

Cabbage, carrot, pea, cauliflower and brinjal are the five different plants based meals. In these meals, vegetables are used which are the parts of plant. We know that vegetables are very healthy and nutritive which can be get from plants.

So we can conclude that dish of Cabbage, carrot, pea, cauliflower and brinjal are the meals we could enjoy that contain only plant products.

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