Which of the following is considered a contact force?
Group of answer choices

friction between an object and chair

the force between two magnets

the force between two charged particles

the gravitational pull of a planet

Answer:

Noble Gases

Explanation:

Noble gases are very unreactive because they already have a full valence shell and therefore, do not need to bond.

Answer:

Noble gases

Explanation:

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Explanation:

The concentration of Bovine Hb with absorbance 0.7 at 570 nm has been 2.264 [tex]\mu[/tex]M.

According to Beer's law, the absorbance of the sample can be given by:

Absorbance = Extinction coefficient [tex]\rm \times[/tex] concentration [tex]\times[/tex] path length

The Bovine Hb has the extinction coefficient = 30910 L/mol/cm

The absorbance = 0.7

The path length has been 1 cm.

The concentration of the Bovine Hb can be given as:

0.7 = 30910 [tex]\times[/tex] concentration [tex]\times[/tex] 1

The concentration of Bovine Hb = 2.264 [tex]\rm \times\;10^-^6[/tex] moles/L

The concentration of Bovine Hb = 2.264 [tex]\rm \mu[/tex]moles/L

The concentration of Bovine Hb = 2.264 [tex]\mu[/tex]M.

For more information about the concentration on the basis of absorbance, refer to the link:

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Answer:

are called Compounds

Answer:

Compouds

think of a group

an they are alll combined

also "compounds" com-bind = com-POUNDS

Make's sense now?

Answer:

c, maybe d, and I think b.

Explanation:

Im sorry if wrong

Answer:

CuSO4 + 2NH4OH -----> Cu(OH)2 + (NH4)2SO4

Explanation:

Answer:

A chemical change has occurred

Explanation:

Given reaction expression:

      CaCO₃ →  CaO  +  CO₂

The reaction is a decomposition reaction in which a compound is dissociated into simple products.

The reason why the products have different properties than the reactants is because a chemical change has occurred.

The products of the decomposition of calcium carbonate have different properties because a chemical change has occured in the reaction to form new substances.

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Answer:

Ram Ranch

Explanation:

Answer: FLEXUP by lil yacthy and future and playboi carti one of the best songs right now

Explanation:

Answer:

Density = M/V

so 3.81/14.3 .266g/ml

Explanation:

Answer:

True

Explanation:

Answer:

True

True

Temperature

Explanation:

Answer:

Q8) True

Q9) First ionization energy

Q10) A metal oxide

Explanation:

One of the properties of group one elements (alkali metals) is that they combine with water to form basic solutions. E.g 2Na(s)+2H2O(l)→2NaOH(aq)+H2​(g).

An inverse relationship exists between the distance of the outermost electron in the atom from the nucleus and the first ionization energy. As the distance between the outermost electron and the nucleus in group 17 elements increases, their first ionization energies decreases accordingly.

Group 1 elements react with oxygen to yield the corresponding metal oxides. E.g  4 Na + O2 --> 2 Na2O

Answer:

Barium chloride + Sodium phosphate    →   barium phosphate + sodium chloride

Explanation:

Double replacement:

It is the reaction in which two compound exchange their ions and form new compounds.

AB + CD → AC +BD

Chemical equation:

BaCl₂ + Na₃PO₄         →     Ba₃(PO₄)₂ + NaCl

Balanced chemical equation:

3BaCl₂ + 2Na₃PO₄         →     Ba₃(PO₄)₂ + 6NaCl

The cation and anion of both reactants are exchanged with each other.

Ba²⁺ react with PO₄³⁻ and form Ba₃(PO₄)₂ while Cl⁻ react with Na⁺ and form sodium chloride.  

Molecular equation:

Barium chloride + Sodium phosphate    →   barium phosphate + sodium chloride

Answer:

pH = 7.49

Explanation:

This is a buffer solution. We can apply Henderson Hasselbach equation:

pH = pKa + log ((total mmoles - mmoles HCl) / mmoles HCl)

We have the same amount of mmoles.

35 mL . 0.400 M = 14 mmoles HCl

35 mL . 0.400 M = 14 mmoles NaClO

Total moles are 28 mmoles.

We replace data:

pH = pKa + log ((28 mmoles -14 mmoles) / 14 mmoles)

Notice that the relation in log = 1. So pH = pKa

pKa for HClO is 7.49

When pH = pKa we have the same amount of base and acid. Notice, that we have the same mmoles of HCl and NaClO.

Remember that a buffer can be prepared with:

a) A weak acid and its conjugate base (acetic /acetate)

A weak base and its conjugate acid (ammonia/ammonium)

b) A weak acid with a strong base, where the acid can be in excess.

c) A conjugate base (salt from weak acid) with a strong acid, where the base can be in excess. (This case but, the base is not in excess, that's why ph = pKa)

The molecular formula : C₄H₈O₂

Maybe a compound is 54.5% carbon, 9.1% hydrogen and 36.4% oxygen,so :

mol C :

[tex]\tt \dfrac{54.5}{12}=4.54[/tex]

mol H :

[tex]\tt \dfrac{9.1}{1}=9.1[/tex]

mol O :

[tex]\tt \dfrac{36.4}{16}=2.28[/tex]

Divide by 2.28(the smallest ratio) :

C H : O =

[tex]\tt \dfrac{4.54}{2.28}\div \dfrac{9.1}{2.28}\div \dfrac{2.28}{2.28}=2\div 4\div 1[/tex]

The empirical formula : C₂H₄O

(The empirical formula)n=molecular formula

(2.12+4.1+16)n=88

(44)n=88⇒n=2

Answer:

Option C 28 Proton 31 neutron 26 elecrtons

Explanation:

Answer:

Cooling causes contraction and shifting of the fluid particles in the lithosphere.

Answer:

The 2 answer

Explanation:

Answer:

Explanation:

The height of the object can be found by using the formula

[tex]h = \frac{p}{mg } \\ [/tex]

where

p is the potential energy

m is the mass

h is the height

g is the acceleration due to gravity which is 10 m/s²

From the question we have

[tex]h = \frac{23048}{39 \times 10} = \frac{23048}{390} \\ = 59.0974...[/tex]

We have the final answer as

Hope this helps you

The specific heat of the metal : 0.384 J/g° C,

and a metal with a specific heat of 0.384 is copper

The law of conservation of energy can be applied to heat changes, i.e. the heat received / absorbed is the same as the heat released  

Q in = Q out  

Q lost(metal) = Q gained(water)

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

[tex]\tt Q~metal=Q~water\\\\8.5\times c\times (100-23.2)=50\times 4.18\times(23.2-22)\\\\652.8\times c=250.8\Rightarrow c=\dfrac{250.8}{652.8}=0.384~J/g^oC[/tex]

Answer:

1.08 g of water

Explanation:

The balanced chemical equation for the reaction of combustion of methane (CH₄) is the following:

CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g)

According to the equation, 1 mol of CH₄ reacts with 2 moles of O₂. We convert from mol to grams by using the molar masses:

1 mol CH₄ = (1 x 12 g/mol) + (4 x 1 g/mol) = 16 g

2 mol O₂ = 2 x (2 x 16 g/mol) = 64 g

2 mol H₂O = 2 x ((2 x 1 g/mol) + 16 g/mol)= 36 g

From the masses of reactants (CH₄ and O₂), we can see that the stoichiometric ratio is 64 g O₂/16 g CH₄ = 4.

First, we have to identify which reactant is the limiting reactant. We can compare the stoichiometric ratio with the actual reactants ratio (the masses of reactants we have):

1.92 g O₂/0.80 g CH₄ = 2.4

As 4>2.4, we can conclude that O₂ is the limiting reactant.

Now, we consider the stoichiometric ratio between the limiting reactant (64 g O₂) and the product we have to calculate (36 g H₂O), and we multiply the ratio by the actual mass of O₂:

1.92 g O₂ x 36 g H₂O/64 g O₂ = 1.08 g

Therefore, 1.08 g of H₂O will be produced by the chemical reaction of 0.80 g of methane with 1.92 g of oxygen.

Answer:

i think 3

Explanation:

Answer:

Your answer Should be 2

Explanation:

because i need to flex my brain cells

Answer:

C hydrogen and orange boxes element

Explanation:

Answer:

The answer is "Option b".

Explanation:

[tex]\to \text{number of moles} = \frac{\text{number of atoms}}{\text{avogadro number}}[/tex]

                               [tex]= \frac{7.0 \times 10^{19}}{6.0221 \times 10^{23}}\\\\= 1.16 \times 10^{-4} \ moles\\\\ =1.2 \times 10^{-4} \ moles[/tex]

[tex]\to \text{sample mass}= \text{number of moles} \times \text{molar mass}[/tex]

                        [tex]=1.16 \times 10^{-4}\times 58.9\\\\=0.00685 \\\\ = 6.85\ g[/tex]

The molar mass of gas = 206.36 g/mol

In general, the gas equation can be written

[tex]\large{\boxed{\bold{PV=nRT}}}[/tex]

where

P = pressure, atm

V = volume, liter

n = number of moles

R = gas constant = 0.082 l.atm / mol K

T = temperature, Kelvin

mass (m)= 2.89 g

volume(V) = 346 ml = 0.346 L

T = 28.3 C + 273 = 301.3 K

P = 760 mmHg=1 atm

The molar mass (M) :

[tex]\tt PV=\dfrac{m}{M}RT\\\\M=\dfrac{mRT}{PV}\\\\M=\dfrac{2.89\times 0.082\times 301.3}{1\times 0.346}\\\\M=206.36~g/mol[/tex]

Answer:

16.86%

Explanation:

Na3N is sodium nitride.

% of N = mass of N/ molar mass of Na3N *100

% of N = 14/83*100= 16.86%

The percent composition of nitrogen in sodium nitride is 16.86%

Sodium nitride is an inorganic compound that is used in preservatives and antidote for cyanide poisoning.

The molar mass of Na3N is 83 M

The mass of Na3N is 14 g

[tex]% \;of \;N = \dfrac{mass of N}{ molar mass of Na3N } \times 100[/tex]

[tex]\% \;of \;N = \dfrac{mass\; of \;N}{molar\; mass\; of\; Na3N} \times 100\\\\\\\% \;of \;N = \dfrac{14}{83} \times 100 = 16.86\%[/tex]

Thus, the  percent composition of nitrogen in sodium nitride is 16.86%.

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Answer:

Avogadro's law (sometimes referred to as Avogadro's hypothesis or Avogadro's principle) is an experimental gas law relating the volume of a gas to the amount of substance of gas present.[1] The law is a specific case of the ideal gas law. A modern statement is:

Avogadro's law states that "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules."[1]

For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant.

The law is named after Amedeo Avogadro who, in 1812,[2][3] hypothesized that two given samples of an ideal gas, of the same volume and at the same temperature and pressure, contain the same number of molecules. As an example, equal volumes of molecular hydrogen and nitrogen contain the same number of molecules when they are at the same temperature and pressure, and observe ideal gas behavior. In practice, real gases show small deviations from the ideal behavior and the law holds only approximately, but is still a useful approximation for scientists.

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Answer:

Natural gas

Explanation:

Natural gas is a gaseous fossil fuel produced from organic matter that is used to heat homes and cook food.

Natural gas is one of the most volatile part of hydrocarbons that exist together with fossil fuel.

Answer:

P₂ = 2.60 atm

Explanation:

Given data:

Initial pressure = 2.38 atm

Initial temperature = 25.0 °C

Final pressure = ?

Final temperature = 52.78°C

Solution:

Initial temperature = 25.0 °C (25.0+273 = 298 K)

Final temperature = 52.78°C (52.78+273 = 325.78 K)

According to Gay-Lussac Law,

The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.

Mathematical relationship:

P₁/T₁ = P₂/T₂

Now we will put the values in formula:

2.38 atm / 298 K = P₂/325.78 K

P₂ = 2.38 atm × 325.78 K  / 298 K

P₂ = 775.35 atm. K /293 K

P₂ = 2.60 atm