How many moles are there in 3.9 grams of potassium

Answer:

88 g

Explanation:

32 g of CH4 react with 128 g of O2, producing 88 g of CO2.

Answer:

Yes

Explanation:

Yes, there are many energy forces that directly affect the formation of rocks and other substances. The Sun itself provides both energies in the form of heat/radiation and magnetic energy. Heat can get so intense when combined with pressure from being so far underground that it causes rocks to melt and become magma, which combines with other minerals and forms new types of rocks when they cool in the future. Magnetic energy helps push and pull the waves and wind on Earth which ultimately break down rocks into sand over the years.

Answer:

D: fussion

Explanation:

The process called nuclear fussion.

for example, four hydrogen atoms combine in a nuclear fussion reaction to form one helium atom.

Answer:

hi

Explanation:

Answer:

Fleshy Fruits: All of most of the ovary wall (pericarp) is soft or fleshy at maturity. ... partitions, juicy seed vesicles, and a leathery exocarp similar to a hesperidium. ... This is a very common dry fruit found in many different plant families.

Explanation:

Answer:

Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.

Answer:

2.A baby grasshoper is a nymph.

Explanation:

Answer:

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Answer:

2.A baby grasshopper is a nymph.

Explanation:

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Answer:

the answer to this question here is A

Explanation:

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Answer:

Acid and Salt

Explanation:

Common hydrogen compounds

Hydrogen combines with other elements, forming a number of compounds, including common ones such as water (H2O), ammonia (NH3), methane (CH4), table sugar (C12H22O11), hydrogen peroxide (H2O2) and hydrochloric acid (HCl), according to Jefferson Lab.

The car is not accelerating, because the car is driving at a constant speed of 20 miles per hour.

Answer:

The answer is 39.99711. We assume you are converting between grams NaOH and mole. You can view more details on each measurement unit: molecular weight of NaOH or mol This compound is also known as Sodium Hydroxide.

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 0.44moles are there in 17.6g NaOH.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. The stoichiometry represents the number of moles.

Mathematically,

number of moles of NaOH =given mass of NaOH÷ molar mass of NaOH

Molar mass of 1 mole of NaOH= 40 g/mol

mass of NaOH=  17.6g

Substituting all the given values in the above equation, we get

number of moles of NaOH = 17.6g ÷  40 g/mol

number of moles of NaOH  =0.44moles

Therefore, 0.44moles are there in 17.6g NaOH.

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Environmental changes affect animals depending on their ability to adapt to new conditions.

An adaptation is any type of phenotypic feature associated with a higher fitness in a particular environment.

Adaptations are features that allow organisms to adapt to challenging environmental conditions.

In conclusion, environmental changes affect animals depending on their ability to adapt to new conditions.

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Explanation:

When insulating materials rub against each other, they may become electrically charged . Electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. The material that gains electrons becomes negatively charged. The material that loses electrons is left with a positive charge.

Answer:

The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants. This stored chemical energy, or heat content, of the system is known as its enthalpy.

Explanation:

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Answer:

here is what i put for this project:

The reaction in this project is exothermic. The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants. This stored chemical energy, or heat content, of the system is known as its enthalpy. The potential energy in reactants is higher than the potential energy of products in an exothermic reaction. Since energy is given off, the products are lower in energy than the reactants. The energy that is given off is a result of the formation of new bonds.

The change of the enthalpy happening in the chemical reaction is different from the pathway in between the initial and the final states. The addition of the equation gives the net change of the enthalpy. Enthalpy change is the amount of heat evolved or absorbed in the reaction under constant pressure. This can be calculated by checking the amount of heat evolved during the reaction. This reaction occurs at a constant pressure.

Explanation:

"The skeletal system works as a support structure for your body. It gives the body its shape, allows movement, makes blood cells, provides protection for organs and stores minerals"

Answer: 52Te - Tellurium

Explanation: Radioactivity occurs when an unstable nucleus of an element decompose into a stable element by emitting particles or forms of eletromagnetic energy. There are types of radioactivity and Spontaneous Fission is one of them.

In Spontaneous Fission, the unstable, also called parent, nucleus splits into two smaller nuclei and emitts one or more neutrons.

The reaction spontaneous fission of Cf is represented below.

25498Cf ⇒ 11846Pd + 4n + X

The characteristics of each element of the equation are:

1) The element Cf has atomic mass 254 and atomic number 98.

2) Element Pd has atomic mass 118 and atomic number 46.

3) Neutron is represented as n, has no atomic number and atomic mass 1.

Given these properties, to determine the other nuclide, we have to find out the nuclide's atomic number, as each element in the periodic table has its own atomic number.

At the left side of the equation, atomic number is 98. At the right side, element X's atomic number is

98 - 46 + 0 = 52

In the periodic table, the element with atomic number 52 is Tellurium, whose symbol is Te.

The other nuclide for the spontaneous fission is Tellurium (Te).

Answer:

121.5g

Explanation:

from the equation:

2mol of Al react to give 3 mol of Zn

i.e 81g of Al will give 3×81/2 = 243/2 = 121.5g

Answer:

Answer: The bold staircase in the periodic table allows us to classify which elements are metalloids.

Explanation: Additionally, it acts like a "divider" that allows us to properly distinguish the metals from the non-metals in the periodic table.

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Answer:

In a physical change, the substances involved retain their original properties. A new substance is not formed. A physical change can be reversed. Chemical changes happen on a molecular level when two or more substances chemically bond together.

Mending a broken bone  is a chemical change as to heal the bone enzymes are released which are chemicals.

Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.

There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.

There are three types of chemical changes:

1) inorganic changes

2)organic changes

3) biochemical changes

During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.

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Answer:

purifying copper to produce copper wiring for homes

Explanation:

Answer:

b.purifying copper to produce copper wiring for homes

Explanation:

Answer:

See explanation

Explanation:

All physical quantities are broadly classified into scalar quantities and vector quantities.

Scalar quantities have magnitude but do not have direction. Vector quantities have both magnitude and direction. Hence the main difference between a scalar quantity and a vector quantity is that a vector has direction while a scalar quantity does not.

Speed is a scalar quantity while velocity is a vector quantity. You have just specified a magnitude of 200 mph without mentioning its direction. This implies that you are referring to speed of the cars in the race and not velocity because velocity of the cars must indicate the direction!

Answer:

Chemical change.

Explanation:

When it is heated it decomposes into mercury and oxygen gas. The mercury oxide reactant becomes the silver color of mercury. Hence, a color change can be noticed throughout the reaction.

Answer:

chemical change

Explanation:

The boiling point of water increases as the amount of impurities dissolved in it increases. For our purposes, we will consider the non-electrolyte to be the dissolved impurity. The change in the boiling point can be calculated using the equation:

[tex]\Delta T_b = i \times K_b \times m[/tex]

where [tex]\Delta T_b[/tex] is the change in boiling point, [tex]i[/tex] is the van ‘t Hoff factor (whose value denotes the number of particles each formula unit of the dissolved substance dissociates into in water), [tex]K_b[/tex] is the boiling point elevation constant, and [tex]m[/tex] is the molality (moles of solute/kilogram of solvent) of the solution.

Right off the bat, since we're dealing with a non-electrolyte, the dissolved substance can be assumed not to dissociate in water. So, our van ‘t Hoff factor, [tex]i[/tex], would be 1 (by contrast, the [tex]i[/tex] for an ionic compound like NaCl would be 2 since, in water, NaCl would dissociate into two particles: one Na⁺ ion and one Cl⁻ ion). We're also given our [tex]K_b[/tex], which is 0.51 °C/m.

Assuming the normal boiling point of pure water to be 100 °C (a defined value for sig fig purposes), the change in boiling point from having dissolved 35.0 g of the non-electrolyte can be obtained by subtracting 100 °C from the final—elevated—boiling point of 101.25 °C:

[tex]\Delta T_b = 101.25\text{ }^o\text{C} - 100\text{ }^o\text{C} = 1.25\text{ }^o\text{C}[/tex]

Now, recall what we're asked to determine: the molecular mass of the dissolved substance. There is one unknown left in the equation: the molality of the solution. Let's first solve for that:

[tex]m = \frac{\Delta T_b}{K_b} = \frac{1.25^\text{ o}\text{C}}{0.51^\text{ o}\text{C}/m} \\ m = 2.45 \text{ mol solute/kg water}.[/tex]

Notice that we didn't include the i since its value is 1.

Now, what would happen if we multiplied our molality by the mass of water we've been given? We would be left with the moles of solute. And what are we asked to find? The molecular mass, or the mass per mole. We can accomplish this in two steps. Remember to convert your mass of water to kilograms:

[tex]2.45 \text{ mol solute/kg water} \times 0.045 \text{ kg water} = 0.110 \text{ mol solute.}[/tex]

And, finally, we divide the mass of our solute by the number of moles of solute:

[tex]\frac{35.0 \text{ g solute}}{0.110 \text{ mol solute}} = 317.5 \text{ g/mol}[/tex]

Our answer to two significant figures (which is the number of sig figs to which our [tex]K_b[/tex] is given) would be 320 g/mol.

Answer:

170 grams NaCl

Explanation:

Find the mass of NaCl by adding the two elements atomic mass

Na: 22.99

Cl: 35.45

22.99+35.45=58.44 g

Convert moles to grams.

2.91 mol NaCl * 58.44 g NaCl= 170.0604 g

Answer:

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I hope this helped! Feel free to add your own little tweaks.

Answer:

B

Explanation:

Answer:

1.584e10 = 15,840,000,000,000

Explanation:

250,000 miles

multiply the length value by 63360

25e4 x 63360

= 1.584e10

Answer: 110000000 inches

Explanation: Since the moon is 1,320,000,000ft away from the earth you divide 1,320,000,000ft  with 12 to get your final answer 110000000