2. Using the following data, calculate the average atomic mass of magnesium (give your answer to the nearest
.01 ) : Show all work!
Isotope: Mg Percent abundance: 78.70%
24
Isotope: 'Mg Percent abundance: 10.13% 25
Isotope: Mg Percent abundance: 11.17% 26

Answer:

D = 2.9 g/mL

Explanation:

Density = Mass over Volume

D = m/V

Step 1: Define

m = 58 g

V = 20 mL

D = unknown

Step 2: Substitute and Evaluate for Density

D = 58 g/20 mL

D = 2.9 g/mL

To do this measure called molarity is commonly used. Molarity (M) is defined as the number of moles of solute (n) divided by the volume (V) of the solution in liters. It is important to note that the molarity is defined as moles of solute per liter of solution, not moles of solute per liter of solvent.                    

so the answer is D.

hope this helps have a great day....!

According to the concept of molar concentration, molarity is  defined as the number of moles of a dissolved substance.

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.

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Answer:

The six most common elements in living things are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur. Atoms of these elements combine and form thousands of large molecules. These large molecules make up the structures of cells and carry out many processes essential to life.

Explanation:

hope that helped

Different elements combine together to form an organism and other essential organic and inorganic molecules for the life and survival of organisms.

In multicellular organisms, such as animals, atoms form molecules by coming together. These atoms are present in the elements. Molecules can interact to form cells. Cells combine to form tissues, which make up organs.

At the most basic level, all organisms are made of a combination of elements:

Thus, Different elements combine together to form an organism and other essential organic and inorganic molecules for the life and survival of organisms.

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Answer:

C

Explanation:

solid snow melts; liquid water evaporates; gaseous water vapor condenses; water freezes; precipitation of frozen water (snow) back to Earth

only cycle that makes sense

Answer:

The answer is C

Explanation:

Answer:

D.They are based on current knowledge.

Explanation:

Guy above me is wrong

Answer:

B. Iron (7.8 g/mL)

Explanation:

23.4/3 = 7.8

7.8g/mL

The identity of a sample of a metal that has a mass of 23.4 g and a volume of 3.0 mL is iron with a density of 7.8g/mL.

The density of a substance can be calculated by dividing the mass of the substance by its volume. That is;

Density = mass (g) ÷ volume (mL)

According to this question, a sample of a metal has a mass of 23.4 g and a volume of 3.0 mL. The density of the metal is as follows:

Density = 23.4g ÷ 3mL

Density = 7.8g/mL

Therefore, the identity of a sample of a metal that has a mass of 23.4 g and a volume of 3.0 mL is iron with a density of 7.8g/mL.

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Answer:

I think its a World War.

Explanation:

This is just what my sister told me, since the cost for the war could make a country poor and the damage it could cause could lead a country to disaster.

i think d answer is tsunami

Answer:

[tex]speed = \frac{distance}{time}[/tex]

Answer:

(C) releases energy

Explanation:

From Bohr's model of the atom, we can understand the energy transitions involved when an electron moves from one energy level to another.

(C) releases energy

From Bohr's model of the atom:

We can understand the energy transitions involved when an electron moves from one energy level to another.

Therefore, option C is correct.

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Answer:

92.65256 cm^3

Explanation:

To find this, we can simply multiply all three dimensions to get the answer in cubic centimeters, and we get the answer above. If you want to be more specific, we can go by the sigfig rule and the answer would be rounded to 93 cm^3.

A hydrogen atom contains 1 electron, 1 proton

Explanation:

Answer:

3

Explanation:

It is in the third column or group on the periodic table

Answer:

Hydrogen sulfide is an newly recognized signical molecule with very potent cytoprotective actions.

Answer:

it is 1 because of it is below 7 then it will be dangerous for humans

The pH of the highly corrosive acid, given the data from the question is 1

This is simply a measure of the acidity / alkalinity of a solution.

The pH measures the hydrogen ion concentration while the pOH measures the hydroxide ion concentration

The pH scale is a scale that gives an understanding of the variation of the acidity / alkalinity of a solution.

The scale ranges from 0 to 14 indicating:

NOTE: The lesser the pH of a substance, the more acidic (corrosive) it is and the greater the pH of the substance, the less acidic (corrosive) it is.

With the above information about pH, we can conclude that the pH of the highly corrosive acid, given the data is 1

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Fe²⁺ has the same number of protons as Fe³⁺.

In order to know the number of protons of a species, we need to look for the atomic number (Z) in the Periodic Table.

The atomic number of Fe is 26, so it has 26 protons. Since protons are in the nucleus, they are not lost nor gained. Fe³⁺ results from Fe losing 3 electrons, but it has 26 protons as well.

Taking this into account, let's consider the number of protons of the following species:

A) Mn³⁺. It has 25 protons like Mn (Z = 25).

B) Co²⁺. It has 27 protons like Co (Z = 27).

C) Fe²⁺. It has 26 protons like Fe (Z = 26).

D) Ni. It has 28 protons (Z = 28).

E) Co³⁺. It has 27 protons like Co (Z = 27).

Fe²⁺ has the same number of protons as Fe³⁺.

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Answer:

[tex]Excess=3.53g[/tex]

Explanation:

Hello,

In this case, the undergoing chemical reaction is:

[tex]2Mg(s)+O_2(g) \rightarrow 2MgO(s)[/tex]

Next, we identify the limiting reactant by computing the moles of magnesium oxide yielded by 3.86 g of magnesium and 155 mL of oxygen at the given conditions via their 2:1:2 mole ratios and the ideal gas equation:

[tex]n_{MnO}^{by \ Mg}=3.86gMg*\frac{1molMg}{24.3gMg}*\frac{2molMgO}{2molMg} =0.159molMgO\\\\n_{MnO}^{by \ O_2}=\frac{1atm*0.155L}{0.082\frac{atm*L}{molO_2*K}*275K} *\frac{2mol MgO}{1molO_2} =0.0137molMgO[/tex]

It means that the limiting reactant is the oxygen as it yields the smallest amount of magnesium oxide. Next, we compute the mass of magnesium consumed the oxygen only:

[tex]m_{Mg}^{consumed}=0.0137molMgO*\frac{2molMg}{2molMgO} *\frac{24.3gMg}{1molMg} =0.334gMg[/tex]

Thus, the mass in excess is:

[tex]Excess=3.86g-0.334g\\\\Excess=3.53g[/tex]

Regards!

Answer:

In order to determine the formula of the hydrate, [Anhydrous Solid⋅xH2O], the number of moles of water per mole of anhydrous solid (x) will be calculated by dividing the number of moles of water by the number of moles of the anhydrous solid (Equation

Explanation:

Answer:

Block 1 has a higher density then block 2

Explanation:

Answer:

Yep, the correct answer is C. Block 1 has a higher density than block 2.

Explanation:

Answer:

Distance traveled.

Answer: distance traveled

Explanation: I just got the answer right.

Answer:

Either 12:12:6 or 6:6:12

Explanation:

If I remember correctly the answer should be 6:6:12

Answer:

True

Explanation:

True. If an animal has attributes to it that help it survive better in an environment, it will survive better than its counterparts who do not have this attribute. More survival = More offspring

Answer:

True.

Explanation:

It's called survival of the fittest. Animals are genetically supposed to be well suited to their environment and if they aren't, they die out.

Answer: anhydrous CaCl 2 :0H 2 O

monohydrate CaCl 2 :1H 2 O

a di-hydrate CaCl 2 :2H 2 O

Explanation:

can i please get brainlyest

"the view or belief that the rights and needs of humans are not more important than those of other living things."

Answer:

the view or belief that the rights and needs of humans are not more important than those of other living things.

explanation:

Answer:

Br₂(l) + ΔV → Br₂(g)

Explanation:

When a chemical or phase change occurs during a chemical process some heat is absorbed or released. For the process of vaporization of a substance, the heat (Usually required) is ΔV (How many energy is required for the process occurs).

In the vaporization of Br2 there are required 7.4kcal/mol, Δv. The reaction is:

Answer:

Ca2+(aq)   +  2OH-(aq)  →  Ca(OH) 2 ( s )

Explanation:

The balanced equation is given as;

Ca(NO 3 ) 2 ( aq )  +  2KOH(aq)  →  Ca(OH) 2 ( s )  +  2KNO 3 ( aq )

The net ionic equation features only ions that actually participated in the reaction. These ions are identified due to their change in oxidation numbers. Also, the aqueous compounds are broken down into ions.

Ca2+  + 2NO3-  +  2K+  +  2OH-  →  Ca(OH) 2 ( s ) +  2K+   +  2NO3-

Ions present in both sides of the equation above. These are; NO3-,  K+ and OH-

The net ionic equation is;

Ca2+(aq)   +  2OH-(aq)  →  Ca(OH) 2 ( s )

Answer:

Volume(ml) of drug required = 0.1 ml

So, medicine is safe for this child.

Explanation:      

Given:

Desired dose (D)= 1 mg

Dose in hand (H) = 10 mg

Quantity (Q) = 1 ml

Computation:

Volume(ml) of drug = [Desired medicine / medicine in hand] Quantity.

Volume(ml) of drug required = [1/10]1

Volume(ml) of drug required = 0.1 ml

So, medicine is safe for this child.

Answer:

317.6 mL

Explanation:

Step 1: Write the balanced neutralization equation

MgO + 2 HCl ⇒ MgCl₂ + H₂O

Step 2: Calculate the mass corresponding to 640.0 mg of MgO

The molar mass of MgO is 40.30 g/mol. The moles corresponding to 640.0 mg (0.6400 g) of MgO are:

0.6400 g × (1 mol/40.30 g) = 0.01588 mol

Step 3: Calculate the moles of HCl that react with 0.01588 moles of MgO

The molar ratio of MgO to HCl is 1:2. The moles of HCl are 2/1 × 0.01588 mol = 0.03176 mol

Step 4: Calculate the volume of 0.1000 M HCl that contains 0.03176 moles

0.03176 mol × (1 L/0.1000 mol) = 0.3176 L = 317.6 mL

Answer:

true

Explanation:

photons are emitted when electrons move from from a lower energy level to a higher energy level

Answer:

1) Eₐ = 100.3 kJ/mol

2) k = 7.62×10⁻⁴ M⁻¹s⁻¹

Explanation:

1) Make an Arrhenius graph by plotting ln(k) on the y-axis and 1/T on the x-axis (don't forget to convert temperature to Kelvin).

The slope of the line is equal to -Eₐ/R.

-Eₐ/R = -12065

Eₐ = 100,300 J/mol

Eₐ = 100.3 kJ/mol

2) Since we know the slope of ln(k) vs 1/T is -Eₐ/R, we can say:

-Eₐ/R = (ln(k₂) − ln(k₁)) / (1/T₂ − 1/T₁)

Plug in values and solve for k:

-(108,000 J/mol) / (8.314 J/mol/K) = [ln(k) − ln(1.0×10⁻³)] / [1/(35+273.15 K) − 1/(37+273.15 K)]

-12990 = [ln(k) + 6.91] / (2.09×10⁻⁵ K⁻¹)

-0.272 = ln(k) + 6.91

ln(k) = -7.18

k = 7.62×10⁻⁴ M⁻¹s⁻¹