Tritium (H-3) is a radioactive isotope of hydrogen with a half-life of 12.3 years. How long would it take for a 40.0g sample to decay down to 1.25g

Answer:

The hypothalams

Explanation:

It is the part of the brain that controls the endocrine system.

HOPE THIS HELPED

The hypothalams ~~~~~~

Answer:

Chemical Family means a group of elements in the Periodic Table or, more commonly, compounds that share certain physical and chemical characteristics and have a common name.

A period in the periodic table is a row of chemical elements.

metalloid is an element (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid nonmetals or semiconductors.

Answer:In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction

Explanation:

Answer:

EEEEEeeEEeEEEEEEEeEEEEEEEEEE

Explanation:

e

Answer:

6.19507275608684

Explanation:

Answer:

E

Explanation:

The question is incomplete, the complete question is;

In this stoichiometry problem, determine the percentage yield:

Excess aluminum metal reacts with aqueous nickel(II) sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. In this reaction 108 g of aluminum were combined with 464 g of nickel(II) sulfate to produce 274 g of aluminum sulfate.

Answer:

80%

Explanation:

The correct equation for this reaction is;

2Al(s) + 3NiSO4(aq) --------> Al2(SO4)3 + 3Ni(s)

We already know that Al is in excess then NiSO4 is the limiting reactant.

Hence, Number of moles in 464 g of NiSO4 = mass/ molar mass

Molar mass of NiSO4 = 155 g/mol

Number of moles = 464g/155g/mol = 2.99 moles

Number of moles of Al2(SO4)3 = mass/molar mass

molar mass = 342 g/mol

So, Number of moles = 274g/342g/mol = 0.8 moles

Given the stoichiometric reaction equation;

3 moles of NiSO4 yields 1 mole of Al2(SO4)3

2.99 moles of NiSO4 yields 2.99 * 1/3 = 1 mole of Al2(SO4)3

percentage yield is given by; actual yield/ theoretical yield * 100/1

actual yield =  0.8 moles of Al2(SO4)3

Theoretical yield = 1 mole of Al2(SO4)3

Hence;

% yield = 0.8/1 * 100 = 80%

Answer:

Hydra bud

Explanation:

this plant reproduces asexually

Answer:

0.0045

Explanation:

Scientific notation is the way to express the large value in short form.

The number in scientific notation have two parts.

The digits (decimal point will place after first digit)

× 10 ( the power which put the decimal point where it should be)

for example 4.5×10⁻³

In standard notation

4.5 / 10³

0.0045

The expanded notation is standard notation of writing the numerical values which is normal way. The numbers are written as they are, without the power of 10.

Answer:

6cm^3

Explanation:

240/40=6

6 cm^3

Answer:

The overall ionic formula for a compound must be electrically neutral, meaning it has no charge. When writing the formula for the ionic compound, the cation comes first, followed by the anion, both with numeric subscripts to indicate the number of atoms of each.

Explanation:

This is mind numbing, but I got you.

3NaOH + 1FeCl3 = 1Fe(OH)3 + 3NaCl

3Mg + 2H3(PO)4 = 1Mg(PO4)2 + 3H2

Answer:

(a) Decomposition: A substance breaks down to smaller species. [e.g. CaCO3(s) → CaO(s) + CO2(g) Decomposition of limestone to calcium oxide (quicklime) and carbon dioxide on heating.]

Answer: One formula unit of NaCl consists of one cation, whose chemical symbol is [tex]Na^+[/tex] and one anion whose chemical symbol is [tex]Cl^-[/tex]

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.  

The cation is formed by the metal sodium which forms  [tex]Na^+[/tex] and the anion is formed by non metal chlorine which forms [tex]Cl^-[/tex].

For a formula unit of sodium chloride,  the charges have to be balanced , thus the valencies of ions are exchanged and the neutral compound result. Thus

[tex]Na^+[/tex] and  [tex]Cl^-[/tex] combine to form neutral [tex]NaCl[/tex]

Answer:

The right lower quadrant

The left lower quadrant

Explanation:

Those quadrants contain the ovaries and I just got it correct on the assignment.

Answer:d

Explanation:

Answer:

ye

Explanation:

ye

Answer:

k. e. = 1/2 mv^2

100 = 1/2 * m * 5^2

100 = 1/2 * m * 25

m = 100 *2/25

m = 8 kg

hope it helps you

Answer:

metamorphic

Explanation:

when one rock changes another rock the rock that got changed is now metamorphic

The volume of O₂ produced: 84.6 L

Given

7.93 mol of  dinitrogen pentoxide

T = 48 + 273 = 321 K

P = 125 kPa = 1,23365 atm

Required

Volume of O₂

Solution

Decomposition reaction of dinitrogen pentoxide

2N₂O₅(g)→4NO₂(g)+O₂ (g)

From the equation, mol ratio N₂O₅ : O₂ = 2 : 1, so mol O₂ :

= 0.5 x mol N₂O₅

= 0.5 x 7.93

= 3.965 moles

The volume of O₂ :

[tex]\tt V=\dfrac{nRT}{P}\\\\V=\dfrac{3.965\times 0.082\times 321}{1.23365}\\\\V=84.6~L[/tex]

121 mol CH₄

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Organic

Atomic Structure

Step 1: Define

7.31 × 10²⁵ molecules CH₄

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

[tex]\displaystyle 7.31 \cdot 10^{25} \ molecules \ CH_4(\frac{1 \ mol \ CH_4}{6.022 \cdot 10^{23} \ molecules \ CH_4} ) = 121.388 \ mol \ CH_4[/tex]

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

121.388 mol CH₄ ≈ 121 mol CH₄

Explanation:

When an object undergoes a physical change (solid to liquid, decrease in temperature etc.), the mass of the object remains constant.

When water freezes, the water molecules vibrate closer to one another and there is less space between the molecules.

The same number of water molecules now occupy a smaller volume, therefore their density increases.

The correct answer is the 3rd option.

At the time when the water should be freezed so here the density should be decreased.

The density refers to the mass of the unit volume with respect to the material substance.

The formula for density should be d = M/v

So here d means the density

And, m means mass

V means the volume

So it should be expressed in units with respect to the units of grams per cubic centimeter.

Hence the last option is correct.

Learn more about water here: https://brainly.com/question/24720645

Answer:

I say 20 is ur best option

Answer:

Mass of CO₂ produced = 299.64 g  

Explanation:

Given data:

Mass of CO₂ produced = ?

Mass of propane (C₃H₈) = 100.0 g

Solution:

Chemical equation:

C₃H₈ + 5O₂     →        3CO₂ + 4H₂O

Number of moles of propane:

Number of moles = mass/molar mass

Number of moles = 100.0 g/  44.1 g/mol

Number of moles = 2.27 mol

Now we will compare the moles of propane and carbon dioxide.

                 C₃H₈          :          CO₂

                    1              :            3

                  2.27          :           3/1×2.27  = 6.81 mol

Mass of CO₂:

Mass = number of moles × molar mass

Mass = 6.81 mol × 44 g/mol

Mass = 299.64 g  

Answer:Fe

Explanation:

Answer:

they are either donated to or taken by another atom to achieve octet arrangement

Explanation:

for example Na+ and Cl- .. they both have one extra and one less electron .

so they donate and receive one electron to/from each other to achieve the octet arrangement ..

Answer: D. An increase in entropy

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.

For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.

To overcome a positive enthalpy of solution and allow a solid  solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.

Answer:

"The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups."

Explanation:

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