Question 20 of 66
Which of the following species has the same number of protons as Fe3+?
A) Mn3+
B) Co2+
C) Fe2+
D) Nit
E) CO3+

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:

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

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:

Energy is used when someone is climbing while energy is not used when someone is going down the slope

Answer:

The release into the air of chemicals and particles can cause direct damage to the troposphere (air pollution); alter the composition and function of atmospheric layers (greenhouse effect) or other indirect damages (ozone layer depletion).

Explanation:

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

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:

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

Explanation:

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

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:

a) first group

b) metals

c) K - potassium, Li - lithium

Explanation:

a) they are the alkali metals

b) they're alkali metals lol

c) just look at a periodic table :P

Answer:

3

Explanation:

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

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:

(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:

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:

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.

Learn more about molar concentration,here:

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Answer:

(3.1 x 10^3) (1.00 x 10^7) = 31000000000

Answer:

extensive properties

Explanation:

,such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.

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

Answer:

Explanation:

2Ca    +    O₂   =    2CaO

80 g     32 g         112 g

given amount of Ca = 7.75 g

it will require oxygen =  32 x 7.75 / 80 = 3.1 g

but available oxygen = 2.44 so oxygen is the limiting reagent .

32g oxygen reacts with calcium to give 112 g of calcium oxide

2.44 gram of oxygen reacts with calcium to give 112 x 2.44 / 32 of CaO .

= 8.54 gram .

Theoretical yield of CaO = 8.54 gram.

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:

the answer is: 9.80665

Answer:

Distance traveled.

Answer: distance traveled

Explanation: I just got the answer right.

Answer:

Watts are a measurement of power, describing the rate at which electricity is being used at a specific moment. For example, a 15-watt LED light bulb draws 15 watts of electricity at any moment when turned on. Watt-hours are a measurement of energy, describing the total amount of electricity used over time.

Please mark as brainliest.

Answer: True

Watts are a measurement of power, used in light bulbs and other electricity. It is also measured as candela (C) in SI Units. The answer to the question is true because of this measurement.

Hope this helps!

Answer:

D.

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:

A hydrogen atom contains 1 electron, 1 proton

Explanation:

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:

Molarity = 0.425 M

Explanation:

Given data:

Number of moles = 3.7 mol

Volume of solution = 8.7 L

Molarity of solution = ?

Solution:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

Molarity = 3.7 mol/8.7 L

Molarity = 0.425 M