Sort the examples based on whether they describe a physical change or a chemical reaction. growth of a seed into a seedling tarnishing of silver wax melting from applied heat making caramel by burning sugar grinding wheat to make flour adding copper with gold to make jewelry ​

Answer:

Cu+HNO3

Explanation:

Answer:

1) 1.39 * 10²³ atoms

2) 8.43 * 10²³ electrons

3) 9.73 * 10²³ neutrons

Explanation:

1) 13 g of C-13 contains 6.02 *10²³ atoms

3.00 g of C-13 will contain 6.02 * 10²³ * (3/13) = 1.39 * 10²³ atoms

2) Each atom of C-13 contains 6 electrons

Therefore 3.00 g of C-13 will contain 6 * 1.39 * 10²³  electrons = 8.43 * 10²³ electrons

3) Each atom of C-13 contains 7 neutrons

Therefore, 3.00 g of C-13 will contain 7 * 1.39 * 10²³ neutrons = 9.73 * 10²³ neutrons

Answer:

Density is mass/volume d=m/v   so volume = m/d or mass divided by density.

That would be 23 / 0.7893 = 29.1397 or 29.14 mL.  Grams cancels out

Explanation:

The volume of ethanol is 20.27 g/ml.

The area occupied by a three-dimensional object is its volume. It can be determined using density and mass. Liters are used to measure it. The overall weight of a thing is its mass. M designates it.

The mass per unit volume is known as density. The capital letter D and the symbol rho stand for density. You can figure it out by dividing the mass by the volume.

rho = m / V

rho = density

m = mass

V = volume

Given the mass of the sample of ethanol weighs 16 g

The density of 0.7893 g/mL

Putting the values in the equation

Volume = 16 / 0.7893 = 20.27

Thus, the volume of ethanol is 20.27 g/ml.

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Answer:

1130.89

Explanation:

Answer:

963.648

Explanat:::::::)))))))

Answer:

c. can have a large cumulative effect

Explanation:

Noncovalent interactions between molecules are weaker than covalent interactions. Noncovalent interactions between molecules are of various types which  include van der Waals forces, hydrogen bonding, and electrostatic interactions or ionic bonding.

van der Waals forces  are weak interactions found in all molecules. They include dipole-dipole interactions - formed due to the differences in the electronegativity of atoms - and the London dispersion forces.

Hydrogen Bonds  results when electrons are shared between hydrogen and a strongly electronegative atoms like fluorine, nitrogen, oxygen. The hydrogen acquires a partial positive charge while the electronegative atom acquires a partial negative. This results in attraction between hydrogen and neighboring electronegative molecules.

Ionic bonds result due to the attraction between groups with opposite electrical charges, for example in common salt between sodium and chloride ions.

Even though these noncovalent interactions are weak, cumulatively, they exert strong effect. For example, the high boiling point of water and the crystal structure of ice are due to hydrogen bonding.

Answer:

[tex]\Delta G=-48.2kJ/mol[/tex]

Explanation:

Hello,

In this case, considering that the relationship between Kp and K is:

[tex]K=\frac{Kp}{RT^{\Delta \nu}}[/tex]

Whereas the change in the number of moles (stoichiometric coefficients) is:

[tex]\Delta \nu=1-2-1=-2[/tex]

The equilibrium constant is:

[tex]K=\frac{6.25x10^{-3}}{(8.314\frac{J}{mol\times K}*500.0K)^{-2}}\\\\K=1.08x10^{5}[/tex]

In such a way, the Gibbs free energy of reaction is:

[tex]\Delta G=-RTln(K)=-8.314\frac{J}{mol\times K}*500.0K*ln(1.08x10^5)\\\\\Delta G=-48.2kJ/mol[/tex]

Regards.

Explanation:

loosing or gaining one or more electrons

Answer:

Q1: NO

Q2: NO

Explanation:

Step 1: Given data

Percentage by mass of nitrogen: 46.68%

Percentage by mass of oxygen: 53.32%

Step 2: Divide each percentage by the mass of the element

N: 46.68/14.01 = 3.332

O: 53.32/16.00 = 3.332

Step 3: Divide both numbers by the smallest one (in this case is the same)

N: 3.332/3.332 = 1

O: 3.332/3.332 = 1

The empirical formula is NO. Its molar mass is 30.01 g/mol.

Step 4: Calculate "n"

n = molar mass of the molecular formula / molar mass of the empirical formula

n = (30.01 g/mol) / (30.01 g/mol) = 1

Step 5: Determine the molecular formula

We do so by multiplying the empirical formula by "n".

NO × 1 = NO

Answer:

The value is [tex]P = 7.8 *10^{6} \ Pa [/tex]

Explanation:

From the question we are told that

The internal volume is [tex]V_i = 2.40 \ L = 2.40 *10^{-3} \ m^3[/tex]

The mass of the compound contained is [tex]m = 542 \ g[/tex]

The temperature is [tex]T = 21^o C = 21 + 273 = 294 \ K[/tex]

The critical temperature of silane is [tex]T_c = 269.7 \ K[/tex]

The critical pressure of silane is [tex]P_c = 48.4 bar = 48.4 *10^{5} \ Pa[/tex]

Generally the number of moles of silane inside the cylinder is mathematically represented as

[tex]n = \frac{m}{M}[/tex]

here M is the molar mass of silane with value [tex]M = 32 g/mol[/tex]

So

[tex]n = \frac{542}{32}[/tex]

=> [tex]n = 16.4 \ mol[/tex]

Generally the molar volume of silane in the cylinder is mathematically represented as

[tex]Vn = \frac{V_i}{n}[/tex]

=> [tex]Vn = \frac{2.40 *10^{-3}}{16.4}[/tex]

=> [tex]Vn = 1.42*10^{-4} \ m^3 / mol[/tex]

Generally from Soave-Redlich-Kwon we have that

[tex]P = \frac{RT}{V_n - b} - \frac{a}{V_n (V_n + b)}[/tex]

Here b is a constant which is mathematically represented as

[tex]b = 0.08664 * \frac{R T_c }{P_c}[/tex]

substituting [tex]8.314 J/mol\cdot K[/tex] for R we have \

[tex]b = 0.08664 * \frac {8.314* 269.7}{48.4*10^{5}}[/tex]

[tex]b = 4.0139 *10^{-5} m^3/mol[/tex]

a is also a constant which is mathematically represented as

[tex]a = 0.42748 * \frac{(R * T_c)^2}{P_c} * (1 + m [1-\sqrt{T_r} ])^2[/tex]

Here [tex]T_r[/tex] is the reduced temperature which is mathematically represented as

[tex]T_r = \frac{T}{T_c}[/tex]

=> [tex]T_r = 1.09[/tex]

m is a constant which is mathematically represented as

[tex]m = 0.480 + 1.574w - 0.176w^2[/tex]

=>           [tex]m  =  0.480 + 1.574 (0.094) - 0.176(0.094)^2[/tex]

=> [tex]m = 0.626[/tex]

So

[tex]a = 0.42748 * \frac{(8.314 * 269.7)^2}{48.4*10^{5}} * (1 + 0.626 [1-\sqrt{1.09} ])^2[/tex]

[tex]a = 0.4198[/tex]

From   [tex]P =  \frac{RT}{V_n - b} - \frac{a}{V_n (V_n + b)}[/tex] we have

[tex]P = \frac{8.314 * 294}{1.42*10^{-4} - 4.0139 *10^{-5} } - \frac{0.626}{1.42*10^{-4} (1.42*10^{-4} + 4.0139 *10^{-5} )}[/tex]

[tex]P = 7.8 *10^{6} \ Pa [/tex]

Answer:

6.4 × 10^-10 M

Explanation:

The molar solubility of the ions in a compound can be calculated from the Ksp (solubility constant).

CaF2 will dissociate as follows:

CaF2 ⇌Ca2+ + 2F-

1 mole of Calcium ion (x)

2 moles of fluorine ion (2x)

NaF will also dissociate as follows:

NaF ⇌ Na+ + F-

Where Na+ = 0.25M

F- = 0.25M

The total concentration of fluoride ion in the solution is (2x + 0.25M), however, due to common ion effect i.e. 2x<0.25, 2x can be neglected. This means that concentration of fluoride ion will be 0.25M

Ksp = {Ca2+}{F-}^2

Ksp = {x}{0.25}^2

4.0 × 10^-11 = 0.25^2 × x

4.0 × 10^-11 = 0.0625x

x = 4.0 × 10^-11 ÷ 6.25 × 10^-2

x = 4/6.25 × 10^ (-11+2)

x = 0.64 × 10^-9

x = 6.4 × 10^-10

Therefore, the molar solubility of CaF2 in NaF solution is 6.4 × 10^-10M

The molar solubility should be 6.4 × 10^-10 M

Here

CaF2 will dissociate should be

CaF2 ⇌Ca2+ + 2F-

where,

1 mole of Calcium ion (x)

2 moles of fluorine ion (2x)

Now

NaF will also dissociate like

NaF ⇌ Na+ + F-

Here

Na+ = 0.25M

F- = 0.25M

Now

Ksp = {Ca2+}{F-}^2

Ksp = {x}{0.25}^2

4.0 × 10^-11 = 0.25^2 × x

4.0 × 10^-11 = 0.0625x

x = 4.0 × 10^-11 ÷ 6.25 × 10^-2

x = 4/6.25 × 10^ (-11+2)

x = 0.64 × 10^-9

x = 6.4 × 10^-10

Therefore, the molar solubility of CaF2 in NaF solution is 6.4 × 10^-10M

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Answer:

The value is [tex]x = 0.151 \ e [/tex]

Explanation:

From the question we are told that

The bond length is [tex]l = 1.93\ \r a = 1.93 *1 *10^{-10} =1.93 *10^{-10}\ m [/tex]

The bond dipole moment is [tex] \mu = 1.40 d = 1.40 * 3.33564 *10^{-30} = 4.6699 *10^{-30} \ C \cdot m[/tex]

Generally the dipole moment is mathematically represented as

[tex]\mu = Q * l[/tex]

Here Q is the partial negative charge on the bromine atom

So

[tex]Q = \frac{\mu}{ l}[/tex]

=> [tex]Q = \frac{4.6699 *10^{-30}}{ 1.93 *10^{-10} }[/tex]

=> [tex]Q = 2.42 *10^{-20} C [/tex]

Generally

1 electronic charge(e) is equivalent to [tex]1.60*10^{-19} C[/tex]

So x electronic charge(e) is equivalent to [tex]Q = 2.42 *10^{-20} C [/tex]

=> [tex]x = \frac{2.42 *10^{-20}}{1.60*10^{-19} }[/tex]

=>     [tex]x  =  0.151  \ e [/tex]

Answer:

Explanation:

A pipette is used to measure an exact volume of liquid; a pipette can only measure it's exact recommended volume (it can't measure more or less).

Hence, a 2-mL volumetric pipette can only measure 2 ml and would be recorded as 2.00 (ml). This is because simple volumes are usually recorded in two decimal places.

Answer:

E

Explanation:

burning a substance changes it chemically.

Answer:

9.8 joules

Explanation:

due to acceleration due to gravity

Answer:

Explanation:

The scientific method describes the processes by which scientists gain knowledge about the world. It's characterized by six key elements: questions, hypotheses, experiments, observations, analyses, and conclusions. These elements are interrelated steps, so they don't always function in the same order.

Answer:5.5

Explanation:

Answer:16.38085

Explanation:Aline the decimals then start multiplying.

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Answer:

Explanation:

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Answer:

Everything you can hold, taste, or smell is made of matter. Matter makes up everything you can see, including clothes, water, food, plants, and animals. It even makes up some things you cannot see, such as air or the smell of perfume.

Answer:

Helium is the second element on the periodic table. It is located in period 1 and group 18 or 8A on the righthand side of the table. This group contains the noble gases, which are the most chemically inert elements on the periodic table. Each He atom has two protons and usually two neutrons and two electrons.

Explanation:

thoughtco.com

Answer:

period 1 and group 18 or 8A on the righthand side of the table.

Explanation:

Answer:

phsical

Explanation:

it is a phisical cuz your only changing the shape not the chemical structure

Answer:

2341, last option is the correct choice.

Explanation:

Boiling points of the given compounds are given as:

[tex]CH_4=-161.5\:C^{\circ}\\\\C_4H_{10}=-1\:C^{\circ}\\\\CH_2Cl_2=39.6\:C^{\circ}\\\\H_2O=100\:C^{\circ}[/tex]

Best Regards!

Answer:

Filtration

Explanation:

Filtration is a separation technique used in the laboratories to separate two elements or compounds by using a filter paper and a beaker.

Drierite is also know as calcium sulphate and silicon is made up of silica.

The filtration equipment are taken to separate these two components. The separation method is used in the second beaker by pouring the mixture through a filtering funnel and using a filter paper. The solid remaining of silicon remains on the filter paper separating the two.

Answer:

The answer is

Explanation:

To find the rate in cm/year we must first convert 200 m into cm

1 m = 100 cm

if 1 m = 100 cm

Then 200 m = 200 × 100 = 20 ,000 cm

So the rate is

Reduce the fraction with 10,000

We have the final answer as

Hope this helps you

Answer:

2 CM/year just now got 100 Edge.

Explanation:

Answer:

[tex][OH^-]=9.24x10^{-3}M[/tex].

[tex]pH=11.97[/tex].

Explanation:

Hello,

In this case, since the ionization of methylamine is:

[tex]CH_3NH_2(aq)+H_2O(l)\rightleftharpoons CH_3NH_3^+(aq)+OH^-(aq)[/tex]

The equilibrium expression is:

[tex]Kb=\frac{[CH_3NH_3^+][OH^-]}{[CH_3NH_2]}[/tex]

And in terms of the reaction extent [tex]x[/tex] which is equal to the concentration of  OH⁻ as well as that of CH₃NH₃⁺ via ice procedure we can write:

[tex]3.7x10^{-4}=\frac{x*x}{024-x}[/tex]

Whose solution for [tex]x[/tex] via quadratic equation is 9.24x10⁻³ M since the other solution is negative so it is avoided. Therefore, the concentration of OH⁻ is:

[tex][OH^-]=x=9.24x10^{-3}M[/tex]

With which we can compute the pOH at first:

[tex]pOH=-log([OH^-])=-log(9.24x10^{-3})=2.034[/tex]

Then, since pH and pOH are related via:

[tex]pH+pOH=14[/tex]

The pH turns out:

[tex]pH=14-pOH=14-2.034\\\\pH=11.97[/tex]

Best regards.

Answer:

Atoms of the same element are exactly alike in all respects and are different from atoms of other elements.

Explanation:

One of the postulates of the Dalton's atomic theory is that 'Atoms of the same element are exactly alike in all respects and are different from atoms of other elements.'

Hence, if carbon dioxide from two sources are obtained and analysed, the mass percentage of carbon in both samples should be exactly the same since they both contain atoms of carbon. The atoms of carbon in the both samples are exactly the same in all respects in accordance with the Dalton's atomic theory, hence the observation.