why are copper pipes used in place of old lead pipes for plumbing systems?

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\ [/tex]

From the question

mass = 15.5 g

density = 6.89 g/mL

We have

[tex]volume = \frac{15.5}{6.89} \\ = 2.249637155...[/tex]

We have the final answer as

Hope this helps you

Answer:

valence electrons

Explanation:

The valence electrons are the outer most electrons and the principal energy level in which they belong will vary for .

The chemical element which contains four (4) electrons in its third and outer main energy level is: Silicon (Si).

An electron shell can be defined as the outermost shell of an atom of a chemical element around the atomic nucleus.

Hence, an electron shell is an orbital that is typically accompanied by electrons around the nucleus of an atom.

A sublevel is also referred to as an orbital and it can be defined as an energy level that is associated with the electrons found outside the atomic nucleus.

In Chemistry, there are four main (4) types of sublevel and these are:

In the third (3rd) energy level, there are only three (3) sublevels and these are; s, p and d sublevels.

Silicon is a chemical element that is found in group (4) of the periodic table because it has four (4) electrons in its third and outermost shell.  

In its ground state, Silicon (Si) contains the following number of electrons:

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Answer:

Mercury Atom

Explanation:

If you are talking about what has 121 neutrons and 80 electrons, then it would be a Mercury Atom. Hope this helps!

Answer:

53/26Fe = 0/-1,B + 53/27 Co

Answer:

ΔU = −55.45 kJ

Explanation:

From first law of thermodynamics in chemistry, we have;

ΔU = Q + W

where;

ΔU is change in internal energy

Q is the net heat transfer

W is the net work done

We are given;

Q = 74.6 kJ

But Q will be negative since heat is released

Thus;

ΔU = -74.6 kJ + W

We are given;

Constant pressure; P = 35 atm = 35 × 101325 = 3546375 N/m²

Volume before reaction; Vi = 8.2 L = 0.0082 m³

Volume after reaction; V_f = 2.8 L = 0.0028 m³

Now,

W = -P(V_f - V_i)

W = - 3546375(0.0028 - 0.0082)

W = 19.15 KJ

Thus;

ΔU = Q + W

ΔU = -74.6 kJ + 19.15 KJ =

ΔU = −55.45 kJ

Answer:

33

Explanation:

Answer:

pressure

Explanation:

pressure is the amount of force exerted on an area. when you blow up the balloon you're filling it with gas particles. the gas particles move freely within the balloon and may collide with one another exerting pressure on the inside of the balloon.

The pressure of the gas is the amount of force that is exerted on a balloon by the gas inside the balloon. Therefore, option B is correct.

Pressure can be described as the force applied perpendicular to the surface of a body per unit area. Pressure can be defined as a standard mechanical quantity and is derived from a unit of force divided by a unit of area.

The SI unit of measurement of pressure, the pascal (Pa) or Newton per square meter (N/m²). Pressure can be defined as the amount of force exerted perpendicular to the surface per unit area.

Mathematically, the pressure exerted by force can be calculated as:

[tex]{\displaystyle p={\frac {F}{A}}}[/tex]

where, p is the pressure, F is the magnitude of the normal force, and A is the area of the surface.

Therefore, the amount of force that is exerted on the balloon by the gas inside the balloon is equal to pressure.

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Answer:

To get a boy to like you you have to 1.dress up cutely  

2.talk to him ask him what he likes

3. wear a little bit of make-up not to much

4. wear you hair down and have a little bit of hair on your chest

5. Be really confident and don't wait till a really longg time and mess up like i did.

Explanation:

Answer:

Put your hair down. Also, dont use too much makeup. Just wear mascara and lipgloss. Be kind. Be confident.

Explanation:

If u wear to much makeup he will think ur a try-hard. Stop trying to be cool, it's just dumb. If ur rude, then hes gonna think that u dont like him.

Answer:

[tex]5H_2O+C_5H_{10}O_5\rightarrow 5CO_2+20H^++20e^-[/tex]

Explanation:

Hello.

In this case, when ribose (C₅H₁₀O₅) yields carbon dioxide (CO₂) we write:

[tex]C_5H_{10}O_5\rightarrow CO_2[/tex]

Which needs to be balanced by adding water and hydrogen ions:

[tex]5H_2O+C_5H_{10}O_5\rightarrow 5CO_2+20H^++20e^-[/tex]

You can also see that there are 20 transferred electrons, since the carbon atoms in the ribose have 0 as their oxidation state and the carbon atoms in the carbon dioxide have +4 as the oxidation state, thus, each carbon transfers  4 electrons, a five carbon atoms transfer 20 electrons overall.

In such a way, since the carbon is increasing its oxidation state, such half reaction is an oxidation half reaction.

Best regards.

Answer:

Weather radar is used to locate and track severe storm.

Answer:

Heterogeneous mixture

Explanation:

Soil is composed of small pieces of a variety of materials, so it is a heterogeneous mixture.

Answer:

def compute_volume(pressure,moles,temperature):

    volume = (8.314 * moles * temperature)/pressure

    print("Volume: "+str(volume))

Explanation:

This line defines the function

def compute_volume(pressure,moles,temperature):

This line calculates the volume

    volume = (8.314 * moles * temperature)/pressure

This line prints the calculated volume

    print("Volume: "+str(volume))

Answer:

electron shell is the answer

Answer:

The options are

A.Surroundings get colder and the system decreases in volume.

B.Surroundings get hotter and the system expands in volume.

C.Surroundings get hotter and the system decreases in volume.

D.Surroundings get hotter and the system does not change in volume.

From the Most energy released to the most absorbed , the order is

B. Surroundings get hotter and the system expands in volume.

D. Surroundings get hotter and the system does not change in volume.

C. Surroundings get hotter and the system decreases in volume.

A. Surroundings get colder and the system decreases in volume.

Answer:

[tex]p=26683.2Pa[/tex]

Explanation:

Hello,

In this case, since the pressure is computed via:

[tex]p=h*\rho*g[/tex]

Whereas h is the 0.520-m height, [tex]\rho[/tex] is the 13600-kg/m³ density and the g the 9.81-m/s² gravity. Thus, the pressure in Pa is:

[tex]p=0.20m*13,600 \frac{kg}{m^3} *9.81\frac{m}{s^2} \\\\p=26683.2\frac{kg*\frac{m}{s^2} }{m^2} =26683.2\frac{N}{m^2}\\ \\p=26683.2Pa[/tex]

Best regards.

Answer: here u go

Explanation:

A. 3.7 x 10^4

B. 4.56 × 10^-8

C. 8.01 × 10^6

Work for A:

Step 1

To find a, take the number and move a decimal place to the right one position.

Original Number: 37,000

New Number: 3.7000

Step 2

Now, to find b, count how many places to the right of the decimal.

New Number: 3 . 7 0 0 0

Decimal Count:   1 2 3 4

There are 4 places to the right of the decimal place.

Step 3

Building upon what we know above, we can now reconstruct the number into scientific notation.

Remember, the notation is: a x 10b

a = 3.7 (Please notice any zeroes on the end have been removed)

b = 4

Now the whole thing:

3.7 x 104

Step 4

Check your work:

104 = 10,000 x 3.7 = 37,000

Work for B:

Step 1

To find a, take the number and move a decimal place to the right one position.

Original Number: 456

New Number: 0.0000000456

Step 2

Now, to find b, count how many places to the right of the decimal.

New Number: 0 . 0 0 0 0 0 0 0 4 5 6

Decimal Count:   1 2 3 4 5 6 7 8 9 10

There are 2 places to the right of the decimal place.

Step 3

Building upon what we know above, we can now reconstruct the number into scientific notation.

Remember, the notation is: a x 10b

a = 4.56

b = 2

Now the whole thing:

4.56 x 102

Step 4

Check your work:

102 = 100 x 4.56 = 456

Work for C:

Step 1

To find a, take the number and move a decimal place to the right one position.

Original Number: 8,010,000

New Number: 8.010000

Step 2

Now, to find b, count how many places to the right of the decimal.

New Number: 8 . 0 1 0 0 0 0

Decimal Count:   1 2 3 4 5 6

There are 6 places to the right of the decimal place.

Step 3

Building upon what we know above, we can now reconstruct the number into scientific notation.

Remember, the notation is: a x 10b

a = 8.01 (Please notice any zeroes on the end have been removed)

b = 6

Now the whole thing:

8.01 x 106

Step 4

Check your work:

106 = 1,000,000 x 8.01 = 8,010,000

Hope this helps!

Answer:

true

Explanation:

Condensation is the opposite of vaporization. True. When does condensation occurs, does a gas lose or gain thermal energy?

Answer:

True

Explanation:

Condensation is formed with moisture and cold air, so the removal of thermal energy, or heat, would create the perfect conditions :)

Answer:

The correct option is C

Explanation:

Chemical equilibrium is a state in which there is no net change in the amount of reactant and products formed over time. This reaction is a reversible reaction, hence the reaction can keep proceeding in either direction until the products formed are equal in mass to that of the reactants or the products been reversed back to the reactants until both sides (product and reactant) achieve equal mass.

Answer:

[tex]Cu_2O[/tex]

Explanation:

Hello.

In this case, since the reaction obeys the law of conservation of mass, since the initial oxide had a mass of 0.500 g and yielded 0.444 g of copper, the mass of oxygen in the oxide is:

[tex]m_O=0.500g-0.444g=0.056g[/tex]

In such a way, we next compute the moles of copper and oxygen by using their atomic masses:

[tex]n_{Cu}=0.444g*\frac{1mol}{63.546 g} =0.00699mol\\\\n_O=0.056g*\frac{1mol}{16.00g}=0.0035mol[/tex]

Next, in order to compute the subscripts of Cu and O on the empirical formula we divide the moles by the fewest moles, in this 0.0035 mol as shown below:

[tex]Cu:\frac{0.00699}{0.0035} =2\\\\O:\frac{0.0035}{0.0035} =1[/tex]

It means that the empirical formula turns out:

[tex]Cu_2O[/tex]

Best regards!

Answer:Because plastic products are durable, they can last for a long time. This makes them affordable because they do not have to be replaced often. On the other hand, the popular use of plastics means that many plastics are thrown away. Plastics litter the ocean, causing harm to marine birds and mammals. Plastic breaks down into plastic dust, which can last for up to a thousand years.

^^^^^copy and paste this part^^^^^

Explanation:Plastic is he hardest material to break down with harm to sea life and land life they may be affordable but costly to the environment.

Answer:

Group number, octet's rule, total number of bonds and fewest valence electrons.

Explanation:

Hello,

For the given statement is answer is bolded:

"When drawing the Lewis structure of a molecule, start by determining the total number of available valence based on each element's group number. Then, use the total number of electrons needed for each element to be stable, generally based on the octet's rule its charge, to determine the total number of bonds by finding the difference between the number of needed and available electrons divided by two.

Next, identify the central atom, which is the element with the fewest valence electrons other than hydrogen. Finally, arrange the number of bonds around the central atom to fulfill the stable number of electrons for each element".

For the first one, it is widely known that the group number provides the number of valence electrons as nitrogen is in group VA and it has five valence electrons, chlorine is in grou´p VIIA and it has seven valence electrons and so on.

For the second one, it is also known that the octet's rule limit the amount of bonds as it has been demonstrated that each compound can hold up to 8 electrons overall excluding some exceptions.

For the third one, based on the octet's rule, an element must have as much bonds as missing electrons to complete eight, for instance, carbon has four valence electrons, so it need four bonds (each one providing one valence electron) in order to attain the octet.

Finally, the central atom must have the fewest number of valence electrons as it shows the other bonds and elements attaining the octet. Usually, the central atom is not demanded to get 8 electrons, for instance in AlCl₃, which is:

[tex]\ \ \ \ \ Cl-Al-Cl\\.\ \ \ \ \ \ \ \ \ \ \ \ \ |\\.\ \ \ \ \ \ \ \ \ \ \ \ Cl[/tex]

Has aluminum as the central one due to the fact that it has three valence electrons whereas chlorine seven and it does not attain the octet.

Best regards.

Answer:

0.307

Explanation:

use the formula of n=mass /molar mass

Answer:

C2H6

Explanation:

Let us first consider the molar Masses of each gas

HBr - 80.91 g/mol

NO2 - 46.0055 g/mol

C2H6 - 30.07 g/mol

We must remember that the greater the molar mass of a gas the lesser its velocity and average kinetic energy.

Looking at the gases listed, C2H6 have the highest average kinetic energy at this temperature since it has the lowest molecular mass. This reasoning is directly derived from Graham's law of diffusion in gases.

Hence C2H6 will effuse fastest when a hole is made in the container. It also possess the greatest average kinetic energy because it has the lowest molecular mass.

Answer:

you can see the empirical formula at the pic

The empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.

Empirical formula of a compound is defined as the simplest whole number ratio of atoms present in a compound.

(a) 1.245 g Ni : 5.381 g I

Mole of Ni ; Mole of I = 1.245/59 : 5.381/127 = 0.02 : 0.04 = 1:2

So the formula is NiI2

(b) 2.677 g Ba : 3.115 g Br

Mole of Ba : Mole of Br = 2.677/137 : 3.115/60 = 0.019 : 0.038

= 0.02 : 0.04 = 1:2

So the formula is BaBr2

(c) 2.128 g Be : 7.557 g S

Mole of Be : Mole of S = 2.128/9 : 7.557/32 = 0.2 : 0.2 = 1:1

So the formula is BeS

Thus, empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.

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Answer:

N=2

H=6

Explanation:

1.Balance a chemical equation in terms of moles.

2.Use the balanced equation to construct conversion factors in terms of moles.

3.Calculate moles of one substance from moles of another substance using a balanced chemical equation.

The law of conservation of matter says that matter cannot be created or destroyed. In chemical equations, the number of atoms of each element in the reactants must be the same as the number of atoms of each element in the products.

(P.s it could also be where you have to solve it in which you have to simplify it first then solve it.) like adding them all up.

Hope this is the answer. :)

Explanation:

Oxygen will gain electrons to form ion (O²⁻).

Calcium loses electron to form ion (Ca²⁺)

Lithium loses electron to form ion (Li⁺)

Mercury loses electron to form ion (Hg²⁺)

Here it is stated in question that the element will gain electron it means electron bears negative charge.

Therefore,

Option A is correct ✔.

Answer:

heterogeneous

Explanation:

It's a heterogeneous mixture. Diamond is made of just one element: carbon. Each carbon atom in diamond is connected to four other carbon atoms, in a crystal that extends on and on. There are other forms of pure carbon where the atoms are bonded differently, notably charcoal and graphite.

Answer:

heat is mesured in calories and also joules

Explanation: