The half life of a element is 19.4 years. If you start with 50 mg of the element, what mass of the element will remain after 38.8 years?

Answer:

2.67 * 10-3 mol/L

Explanation:

Henry's law is a gas law that states that the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid. The proportionality factor is called Henry's law constant. (Wikipedia)

Given that; C =kP

C= concentration of a dissolved gas = ?

k = Henry's Law constant = 9.71 x 10-4 mol/(L·atm)

P = partial pressure of the gas = 2.75 atm

So,

C = 9.71 x 10-4 mol/(L·atm) * 2.75 atm

C = 2.67 * 10-3 mol/L

Answer:

Much of Earth's energy comes from the Sun.

Explanation:

Nearly all life on Earth depends on solar energy since plants use sunlight to make food through the process of photosynthesis. Photosynthesis was the process that fed plants and animals, which in turn, over the course of millions of years, became fossil fuels.

Answer:

Hotspots occur when one of the Earth's plates moves over an unusually hot part of the Earth's mantle. These hot areas are usually relatively stationary and result in large amounts of magma rising up, piercing a hole in the plate to form a volcano. As the plates move, a series of volcanoes can form.

Answer:

B.A Solution with a pH greater than 7

Answer:

A

Explanation:

A "Basic solution" Or a base solution is a solution that has less than a level 7 of pH levels

So the answer would be A

Answer: it is Sulphur, S

Explanation:

Answer:

Drd

Explanation:

Answer:

it's definitely a oxidation reaction because here the oxygen contained OH group present in yeild

Answer:

B.

Explanation:

I had this same question today and got it right

Answer:

Genetic variability of offspring

Explanation:

Basically the sorting of genes

Answer:

carbon...?

Explanation:

Answer:

Carbon

Explanation:

Carbon makes up most of the building blocks of life.  Hope that is right. Good luck

Answer:

compound

Explanation:

Convert 10g of NaOH to moles using the molar mass.

10 g NaOH / 39.997 g/mol NaOH = 0.25 mol NaOH

NaOH is a strong base so it dissolves completely in solution, so you’ll have 0.25 mol of OH-. Calculate the molarity of OH-.

0.25 mol OH / 0.250 L = 1.0 M OH-

Calculate the pOH. pOH = -log(1.0) = 0

pH = 14 - pOH = 14

Answer:

B the atmosphere it's not on earth and I'm pretty sure  the atmosphere doesn't have water in

Explanation:

Answer:

there isnt anything

Explanation:

You have prepared a 1.0 M solution of [tex]CaCl2[/tex] in the laboratory the concentration of chloride ions in the solution is 1.5 M.

Solution is defined as huge amount of solute dissolved in solvent. The proportion of solute is limited and after reaching at the point of saturation no more solute will be mixed in the solvent. It is impossible to separate solvent and solute from eye.

Pressure plays a important role in rate of reaction to increase the pressure it increases the rate of reaction by increasing the collision.

Pressure increase the concentration of gases it means that it increases the number of molecules per unit volume due to this collision of gases increases this will increase the temperature. This increase of  temperature will increase the rate of reaction.

Therefore, you have prepared a 1.0 M solution of CaCl2 in the laboratory the concentration of chloride ions in the solution is 1.5 M.

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Molarity

Chemists primarily need the concentration of solutions to be expressed in a way that accounts for the number of particles that react according to a particular chemical equation. Since percentage measurements are based on either mass or volume, they are generally not useful for chemical reactions. A concentration unit based on moles is preferable. The molarity (M) of a solution is the number of moles of solute dissolved in one liter of solution. To calculate the molarity of a solution, you divide the moles of solute by the volume of the solution expressed in liters.

Note that the volume is in liters of solution and not liters of solvent. When a molarity is reported, the unit is the symbol M and is read as “molar”. For example a solution labeled as 1.5 M NH 3 is read as “1.5 molar ammonia solution”.

Sample Problem: Calculating Molarity

A solution is prepared by dissolving 42.23 g of NH 4 Cl into enough water to make 500.0 mL of solution. Calculate its molarity.

Step 1: List the known quantities and plan the problem.

& underline{text{Known}} &&underline{text{Unknown}} \& text{mass}=42.23 text{g} NH_4Cl && text{molarity}= ? text{ M}\& text{molar mass} NH_4Cl=53.50 text{g} / text{mol} \& text{volume solution}=500.0 text{mL}=0.5000 text{L}

The mass of the ammonium chloride is first converted to moles. Then the molarity is calculated by dividing by liters. Note the given volume has been converted to liters.

Step 2: Solve.

42.23 text{ g } NH_4Cl times frac{1 text{ mol } NH_4Cl}{53.50 text{ g } NH_4Cl} &= 0.7893 text{ mol } NH_4Cl\frac{0.7893 text{ mol } NH_4Cl}{0.5000 text{ L}} &= 1.579 text{ M}

Step 3: Think about your result.

The molarity is 1.579 M, meaning that a liter of the solution would contain 1.579 mol NH 4 Cl. Four significant figures are appropriate.

In a laboratory situation, a chemist must frequently prepare a given volume of solutions of a known molarity. The task is to calculate the mass of the solute that is necessary. The molarity equation can be rearranged to solve for moles, which can then be converted to grams. See sample problem 16.3.

Sample Problem:

A chemist needs to prepare 3.00 L of a 0.250 M solution of potassium permanganate (KMnO 4 ). What mass of KMnO 4 does she need to make the solution?

Step 1: List the known quantities and plan the problem.

Known

molarity = 0.250 M

volume = 3.00 L

molar mass KMnO 4 = 158.04 g/mol

Unknown

mass KMnO 4 = ? g

Moles of solute is calculated by multiplying molarity by liters. Then, moles is converted to grams.

Step 2: Solve.

text{mol KMnO}_4 = 0.250 text{ M KMnO}_4 times 3.00 text{ L} &= 0.750 text{ mol KMnO}_4\0.750 text{ mol KMnO}_4 times frac{158.04 text{ g KMnO}_4}{1 text{ mol KMnO}_4} &=119 text{ g KMnO}_4

Step 3: Think about your result.

When 119 g of potassium permanganate is dissolved into water to make 3.00 L of solution, the molarity is 0.250 M.

Answer:

0.087 g/cm^3

Explanation:

Density is Mass : Volume.

Volume = 12 x 8 x 9 = 864 cm^3

Mass = 75 g

Density = 75g/864 cm^3 = 0.087 g/cm^3

The density of a 75 g block of wood measuring 12 cm x 8 cm x 9 cm is 8.6 x 10⁻⁵ Kg/cm³.

Density is defined as the mass per unit volume of the body. Mathematically-

ρ = M/V

Given is a 75 g block of wood measuring 12 cm x 8 cm x 9 cm.

We can write -

Mass = [m] = 75 g = 75/1000 = 0.075 Kg

Volume = [V] = L x B x H = 12 x 8 x 9 = 864 cm³

Therefore, the density of the object will be -

ρ = M/V

ρ = 0.075/864

ρ = 8.6 x 10⁻⁵ Kg/cm³

Therefore, the density of a 75 g block of wood measuring 12 cm x 8 cm x 9 cm is 8.6 x 10⁻⁵ Kg/cm³.

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Answer:

D is the most soluble in water at 60 degrees Celsius

According to the data given in the table, the salt is most soluble at 60o C - salt D.

In the given table it is given that all the salts are soluble in different concentrations in different concentrations of the water at the same temperature of 60 degrees celsius.

Converting them in the same amount of H₂O that is 100 grams in the same ratio:

Thus, the salt D is the most soluble that is 50 grams per 100 gram H₂O.

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Answer:

One way is that carbon dioxide automatically dissolves in cold ocean surface waters anyway so large bodies of water already have a concentration of carbon dioxide. Another way is when carbon dioxide dissolves in rainwater which later reacts with minerals in rocks. These rocks then get carried away by rivers or streams into bigger bodies of water and the carbon is transported through the minerals in the rocks.

Answer:

sorun nedir anlamıyorum seni türkçe yaz

Answer:

1.09 moles

Explanation:

Sodium has a molar mass of 23 grams per mole. To get the number of moles of sodium, divide 25 grams by 23 grams per mole. The answer is 1.09 moles

Answer:37

Explanation:

Because mass number is proton number + neutron number

The person who looks at the different area managers in a large corporation such as in HR, Business Information and Operations is known as a general manager.

An organizational structure can be described as the process which involves dividing an organization into several functional units. A functional organizational structure is a kind of structure used to organize staff by categorizing them into several departments based on their roles or functions, skill sets, and knowledge.

These departments are vertically structured and may include IT, sales, finance and marketing, research, customer service, etc. The various departments are headed by functional managers who have the responsibility of managing, overseeing, and reporting to the executive management.

A manager is an individual who has the responsibility of providing guidance,  supervision, support, and administrative control, as well as acting as a role model to the employees working in an organization.

Generally, managers are involved in taking up leadership roles and are expected to build strong relationships with their subordinates by providing a fair ground for effective communication and sharing of resources.

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Answer:

The greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.

Explanation:

Greenhouse gases are certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) that trap energy from the sun. Without these gases, heat would escape back into space and Earth's average temperature would be about 60º F colder.

the warming of the Earth's atmosphere that is caused by air pollution. Note: The greenhouse effect occurs when warmth from the sun is trapped in the Earth's atmosphere by a layer of gases (such as carbon dioxide) and water vapor.

Answer:

BECAUSE APPEARS TO REMAIN IN A FIXED LOCATION DUE NORTH WHILE ALL THE OTHER STARS APPEAR TO MOVE AROUND IT.

Explanation:

I'M NOT SURE.CORRECT ME IF WRONG