Help fast I really need it bad

Answer:

By contrast, the red blood cells of mammals lack nuclei and other internal structures found in most animal cells. This simplification allows mammal red blood cells to carry more gas-transporting proteins and to squeeze through smaller blood vessels.

Explanation:

Answer: Braces are used by the people to correct the alignment and position of tooth or teeth in the jaw.

Explanation:

The teeth braces must have strong tensile strength and must create a constant pressure on the teeth so as to allow the straightening of the teeth.

The strong force of attraction between the molecules of the braces material that can be steel, nickel, molybdenum, copper, titanium. This makes the bracing material rigid on the teeth.

Answer:

it would be dermatology

Explanation:

the first two dont make sense, and a dermatologist is the doctors themselves, so therefore dermatology is the study of it

Answer:

71.25 g

Explanation:

Methane + Sulfur = Carbon Disulfide + Hydrogen Sulfide

The equation is given as;

CH4 + S --> CS2 + H2S

Upon balancing, we have;

CH4(g) + 4S(s) → CS2(l) + 2H2S(g)

Theoretical yield of carbon disulphide;

Equal masses of 120g

The limiting reactant is sulphur It determines how much of the product is formed.

From the equation;

4 mol of S produces 1 mol of CS2

upon converting to masses using; Mass = number of mol * Molar mass

4 mol of S = 4 * 32

1 mol of CS2 = 76g

128g of S produces 76g of C2, 120g would produce ?

128 = 76

120 = x

x = 120 * 76 / 128

x = 71.25g

(a).  The balanced chemical reaction will be:

[tex]\rm CH_4\;(g)+\;4\;S\;(s)\rightarrow\;CS_2\;(l)+\;2\;H_2S\;(g)[/tex]

(b). 120 grams of sulfur will produce 71.25 grams of carbon disulfide.

The heating of methane in the presence of sulfur can be given by:

[tex]\rm CH_4\;+\;S\;\rightarrow\;CS_2\;+\;H_2S[/tex]

(a). The lowest possible coefficients have been used to balance the number of elements on both sides i.e. reactant and the product.

[tex]\rm CH_4\;+\;4\;S\;\rightarrow\;CS_2\;+\;2\;H_2S[/tex]

The state of the elements has also been mentioned in the chemical equation. The state of methane is gas, sulfur is solid, carbon disulfide is liquid and hydrogen disulfide is gas.

Thus the balanced chemical reaction will be:

[tex]\rm CH_4\;(g)+\;4\;S\;(s)\rightarrow\;CS_2\;(l)+\;2\;H_2S\;(g)[/tex]

(b). When 120 grams of sulfur reacts, the yield of carbon disulfide will be:

From the balanced equation, 4 moles of sulfur will give 1 mole of carbon disulfide.

4 moles of Sulfur = mole [tex]\times[/tex] molecular weight

4 moles of Sulfur = 4 [tex]\times[/tex] 32

4 moles of Sulfur = 128 grams.

1 mole of carbon disulfide = 76 grams.

So, 128 grams of sulfur produces, 76 grams of carbon disulfide.

Thus, 120 grams of sulfur will produce = [tex]\rm \dfrac{76}{128}\;\times\;120[/tex] grams Carbon disulfide

120 grams of sulfur will produce = 71.25 grams of Carbon disulfide.

Thus, 120 grams of sulfur will produce 71.25 grams of carbon disulfide.

For more information about a chemical reaction, refer to the link:

https://brainly.com/question/1689737

Answer:

6,765 years

Explanation:

Calculation to determine the age of the piece of wood in years

First step is to calculate decimal fraction of Carbon-14 that was remaining

Decimal fraction of Carbon-14= 6.00 counts per minute per gram/ 13.6 counts per minute per gram

Decimal fraction of Carbon-14 remaining= 0.4411765

Second step is to calculate the numbers of half-lives that have elapsed

(1/2)^n= 0.4411765

Hence,

n log 0.5 = log 0.4411765

n = 1.18057

Last step is to calculate the length of time that has elapsed

Using this formula

Elapsed length of time=Half life of carbon-14 *n

Let plug in the formula

Elapsed length of time=5,730 years * 1.18057

Elapsed length of time= 6,765 years

Therefore the age of the piece of wood in years will be 6,765 years

Answer:

i hope it helps

Explanation:

This reaction involve an acid (HCl) reacting with a base (NaOH), producing a salt (NaCl) and water. Therefore it's a neutralization reaction.

Answer:

unpaired

homolysis

more

initiator

allylic substitution

radical

increases

faster

inhibitor

addition

ionic

with

Explanation:

The list of suitable words to be used to fill in the blank spaces in the sentences have been shown in the image attached.

A radical is any specie that contains an unpaired (odd) electron. Radicals are formed by homolysis of covalent bonds.

Due to the double bond involved in resonance, allylic radicals are more stable than tertiary radicals although stability of radical increases with the number of alkyl groups present. Initiators easily supply free radicals for radical reactions.

Addition reactions are faster with Cl2 than with Br2 because chlorine is more reactive than bromine. The addition of Br2 to cyclohexene occur via ionic mechanism and ionic intermediates.

Radical halogenation reactions occur with racemization at a stereogenic center.

Answer:

Number of delocalized electrons

Explanation:

Magnesium has more delocalized electrons compared to sodium and this accounts for the higher melting point.

Answer:

pH = 5.19, at the equivalence point

Explanation:

This is titration of a weak base and a strong acid. pH in the equivalence point will be acid. To determine this pH, we know that in in the equivalence point:

mmoles base = mmoles of base

50 mL  . 0.3M = 0.150 M . Volume of acid

Volume of acid = (50 . 0.3)/ 0.15 → 100 mL

Total volume of equivalence point is 50 mL + 150 mL = 200 mL

Neutralization reaction is:

NH₃ + HCl → NH₄Cl

NH₃ +  H₃O⁺ ⇄  NH₄⁺  +  H₂O

15          15

0           0            15

Ammonia's Kb = 1.8×10⁻⁵

In the equivalence point, we have only ammonium, beacuse all the amonia reacted to the protons. Let's make the equilibrium

      NH₄⁺  +  H₂O  ⇄  NH₃  +  H₃O⁺      Ka

I:      15            -             -            -

Eq:  15-x                        x           x

Ka = 1×10⁻¹⁴ / Kb → 5.55×10⁻¹⁰

[NH₄⁺] = 15 mmoles / 200 mL = 0.075 M

In the equilibrium, we can avoid the 15 - x, because Ka is soo small.

Expression for Ka is [ NH₃ ] .  [H₃O⁺] /  [NH₄⁺] = 5.55×10⁻¹⁰

[H₃O⁺] = √(5.55×10⁻¹⁰ . 0.075)

[H₃O⁺] =  6.45×10⁻⁶

- log [H₃O⁺] =  pH → 5.19

Answer:

47

Explanation:

Answer:

A

Explanation:

Hot air is less dense therefore it rises. Cold air is more closely packed therefore it is more dense. Less dense things rise while more dense things sink.

Answer:

A

Explanation:

Think of it like an hot air balloon

Hot air makes it rise and cool air sinks it downwards

Answer:

(Nothing)-But No answer

Answer:

A mixture is the blending of two or more dissimilar substances. A major characteristic of mixtures is that the materials do not chemically combine. Mixtures can be divided into those that are evenly distributed (homogeneous) and those that aren't (heterogeneous).

Explanation:

Answer:

A mixture is the blending of two or more dissimilar substances. A major characteristic of mixtures is that the materials do not chemically combine. Mixtures can be divided into those that are evenly distributed (homogeneous) and those that aren't (heterogeneous

Answer:

i think that it is. d and b, im not completely sure but ik d is included

Explanation:

Answer:

think b and a

Explanation:

Answer:

Ms word is a type of application that is used to make your work more easier nd attractive.

Explanation:

For ex- you can draw a line,you can highlight your text,make your text bold and you can also increase and decrease the font size.

Answer:

0.75moles of  H₄SiO₄

Explanation:

Given parameters:

Number of moles of H₂O  = 1.5moles

Unknown:

Number of moles of H₄SiO₄  = ?

Solution:

To solve this problem, we need to write the reaction equation first;

            SiO₂  +  2H₂O  →   H₄SiO₄

From the balanced reaction equation:

             2 moles of water will produce 1 mole of  H₄SiO₄

    So     1.5 moles of water will produce [tex]\frac{1.5}{2}[/tex]   = 0.75moles of  H₄SiO₄

Answer:

The answer is B. Limiting factors can lower birth rates, increase death rates.

Answer:

[tex]\Delta H=1149.5J[/tex]

Explanation:

Hello!

In this case, since the calorimeter contains a solution for which the specific heat is 4.18 J/g°C, which is equal to that of the water, we can also notice that the density is 1.00 g/mL and therefore the present mass is 250 g. In such a way, we compute the enthalpy change as shown below:

[tex]\Delta H=mC\Delta T[/tex]

Thus, by plugging in the mass, specific heat and temperature change, we obtain:

[tex]\Delta H=250g*4.18\frac{J}{g\°C}(26.1\°C-25.0\°C)\\\\\Delta H=1149.5J[/tex]

Best regards!

Answer:

i think there are 3 carbon and 5 hydrogen

Explanation:

There are 9 atoms of Oxygen in a molecule of nitroglycerin.

Nitroglycerin is also called Trinitroglycerin, It is an oily, thick, colorless liquid.

A vasodilator, nitroglycerin is generally used to relieve anginal chest pain. Currently, the FDA has approved it for the acute prophylaxis of angina pectoris owing to coronary artery disease as well as the acute alleviation of an episode.

It is used in manufacturing explosives.

The molecular formula of Nitroglycerin is C₃H₅N₃O₉

The chemical formula is 1,2,3-trinitroxypropane.

A molecular formula shows the number of atoms present in the compound.

The number of atoms of Carbon present is 3.

The number of atoms of Hydrogen present is 5.

The number of atoms of Nitrogen present is 3.

The number of atoms of Oxygen present is 9.

So, the total number of atoms of Oxygen present is 9.

To know more about Nitroglycerin

https://brainly.com/question/2563674

#SPJ6

There are 4 lone pairs of electrons present in the carbon dioxide molecule

PLEASE MARK ME AS BRAINLIEST

Answer:

Explanation:

Carbon dioxide, CO2

Each oxygen contributes 2 electrons - 1 for each bond. That means there are a total of 8 electrons around the carbon, in 4 pairs. Because there are 4 bonds, these are all bond pairs.

Answer:

3.04 atoms

Explanation:

because of the switzer theory

Answer: The number of energy levels increases as you move down a group as the number of electrons increases. Each subsequent energy level is further from the nucleus than the last. Therefore, the atomic radius increases as the group and energy levels increase.

Answer:

True

Explanation:

a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.

Answer:

D) particles but the oxygen has a greater mass.

Explanation:

Just took the test and got it right

At STP, one mole of oxygen and one mole of neon contain equal numbers of​ particles but oxygen has greater mass.

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.

It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass  in grams present in one mole  of atoms is its atomic mass.

Learn more about mole,here:

https://brainly.com/question/26416088

#SPJ2

Answer:

c) Fullerene and carbon nanotubes because they have empty spaces inside the  molecules

Explanation:

Fullerene and carbon nanotubes would be the most desired in order to hold the cancer fighting drugs and to carry them through the body safely.