After Dalton's proposed atomic theory, several atomic models were developed. Which model was the first propose the existence of
small, dense nucleus?

Answer:

The autonomic nervous system has a direct role in physical response to stress and is divided into the sympathetic nervous system (SNS), and the parasympathetic nervous system (PNS). When the body is stressed, the SNS contributes to what is known as the “fight or flight” response.

Explanation:

Air that is less dense Speeds up, while air that is more dense Slows Down.

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Answer:

all of they above

Explanation:

Answer:

Usually, the cells are round, elongated or spherical. There are also some cells which are long and pointed on both the ends. Such cells exhibit spindle shape. In some cases, the cells are very long.

Explanation:

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Answer:

Anhydrous sodium carbonate is stable to heat and does not decompose even when it is heated to redness. This is because sodium carbonate salt on heating with acids react to release carbon dioxide.

Mass of a substance = Moles of a substance × molar mass of a substance

We have 0.94 moles of NaHCO3. The molar mass of NaHCO3 is the sum of the atomic masses of the elements comprising NaHCO3, which is approximately 84.007 g/mol.

The mass of 0.94 moles of sodium bicarbonate is therefore (0.94 moles NaHCO3)(84.007 g NaHCO3/mol NaHCO3) = 78.97 ≈ 79 grams of sodium bicarbonate.

Answer:

0.0125 moles of NaOH are present

Explanation:

Molarity, M, is an unit of concentration widely used in chemistry. Is defined as the ratio between moles of solute (In this case, NaOH) and liters of solution.

250.0mL are = 0.250L of solution. As the molarity of the solution is 0.05M = 0.05moles / 1L, the moles present are:

0.250L * (0.05moles / 1L) =

Answer and Explanation:

2 mol of Fe(OH)3 produces 1 mol of Fe2(SO4)3  then 2.1 mol of Fe(OH)3 will produce (1)/(2) x 2.01 = 1.05 mol of Fe2(SO4)3  amount of H2O = (6)/(2) * 2.01 = 6.03 mol HO2

Answer:

The number following the name of the element is the number of subatomic particles inside the nucleus of the atom. This means that it is the mass number of the isotope. The average atomic mass of the element is the sum of the products of the percentage abundance and mass number of the naturally occurring isotopes.

Since, the average atomic mass of the hydrogen is nearest to 1 then, the most abundant isotope should be hydrogen-1.

Answer:

n = 2 moles (1 sig-fig)

Explanation:

Using the Ideal Gas Law equation (PV = nRT), solve for n (= moles) and substitute data for ...

pressure = P(atm) = 100atm

volume =V(liters) = 50L

gas constant = R = 0.08206L·atm/mol·K

temperature = T(Kelvin) = °C + 273 = (35 + 273)K = 308K

PV = nRT => n = PV/RT = (100atm)(50L)/(0.08206L·atm/mol·K)(308K)

∴ n(moles) = 1.978moles ≅ 2 moles gas (1 sig-fig) per volume data (= 50L) that has only 1 sig-fig. (Rule => for multiplication & division computations round final answer to the measured data having the least number of sig-figs).

Moles are the ratio of the mass and the molar mass of the substance. In a 50.0 L cylinder, 2 moles of gas are present at 100 atm and 35 degrees celsius.

An ideal gas equation states the relationship between the moles of the substance, temperature, pressure, and volume. The ideal gas equation is given as,

[tex]\rm PV = nRT[/tex]

Given,

The pressure of the gas (P) = 100.0 atm

Volume of the gas (V) = 50.0 L

Temperature (T) = 308 K

Gas constant (R) =  0.08206 L atm/mol K

Substituting values in equation moles (n) is calculated as:

[tex]\begin{aligned} \rm n&= \rm \dfrac{PV}{RT}\\\\&= \dfrac{100 \times 50}{0.08206 \times 308}\\\\&= 1.978\end{aligned}[/tex]

Therefore, 1.978 or 2 moles of gas are present.

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Answer:

A. "All molecules are compounds, but not all compounds are molecules"

Explanation:

An example of a compound-molecule is oxygen. The elemenal is O, because the periodic table isn't describing molecules, it's describing atoms. The molecule is O2 because it takes 2 O atoms to make a molecule of oxygen.

The primary difference between a molecule and a compound is 'compounds must be composed of more than one type of atom​'.

Explanation:

So, from this, we can conclude that the primary difference between a molecule and a compound is 'compounds must be composed of more than one type of atom​'.

Learn more about molecules and compounds here:

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Answer:

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Answer:

CO2 and H20

Explanation:

The products are on the right hand side of the equation.

Answer:

One of water's most significant properties is that it takes a lot of heat to it to make it get hot. Precisely, water has to absorb 4,184 Joules of heat (1 calorie) for the temperature of one kilogram of water to increase 1°C.

Explanation:

Answer:

Answer:

the veins and arteries are the things that distribute blood throughout your body. There was a lot more blood in the arteries, that's making them very important and should not be cut ever. Veins on the other hand can be cut but you should still not cut them to begin with as if to not lose any blood. They distribute blood throughout your body that comes from your heart and helps muscles skeletal another systems of your body work.

Explanation:

This can be fixed by multiplying the product contacting nitrogen by 2. o The new chemical equation is N2 +H2 →2 NH3. Reactants. Products. Nitrogen. 2. 2.

Answer:

KCrO₃

Explanation:

26.6% K, 35.3% Cr and 33.0% O

The steps in obtaining the empirical formulae from percentage composition is given as;

Step 1:

Divide the percentage composition by the atomic mass of the elements

K = 26.6 / 39.0983  = 0.6803

Cr = 35.3 / 51.9961 = 0.6789

O = 33.0 / 16  = 2.0625

Step 2:

Divide all though by the smallest number (0.6789)

K = 0.6803 / 0.6789 = 1.002

Cr = 0.6789 / 0.6789 = 1

O = 2.0625 / 0.6789 = 3.038

The Empirical formular is the ratio between the elements. This given as;

KCrO₃

Answer:

a: 6 moles

b: 6.75 moles

c: 5 grams

Explanation:

a: mole ratio 2:3

b: mole ratio 2:3

c: mole ratio 2:2

Answer:

c6h12o6 + 6o2 = 6co2 + 6h20

Explanation:

c6h12o6 + 6o2 = 6co2 + 6h20

0 = 18 18

h = 12 12

c = 6 6

Answer:A

Explanation: The universe is always expanding at all times. It dosnt expand that much though, very little

Answer:

In the ring of fire

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