The goal of this lesson is to answer the lesson
question, "What does half-life 'look like' for a
radioactive substance?" Fill in the blanks to
complete the hypothesis.
Hypothesis: If an element is radioactive, then the
fraction of radioactive atoms v remaining after
n half-life cycles should be approximately n
because...

Answer:

65.38 u

Explanation:

hope this helps you out!!!!!!!

They Mean D and not U H just took the test and its D i hope this help

Answer:

d- The resulting pH will be equal to 7 because a strong base will neutralize a strong acid.

Explanation:

The reaction between potassium hydroxide and hydrochloric acid of equal volume and equal concentration yields a solution of pH 7 at equivalence point. We must note that KOH is a strong base while HCl is a strong acid. This fact influences the pH of the system at equivalence point.

Owing to the fact that the acid is exactly neutralized by the base; at the equivalence point of such titration, it is expected that hydrogen ions(H+) and hydroxide ions (OH-) must have reacted to form water, this leads to a final pH of 7.  

Answer:d

Explanation:

240 g of water (specific heat = 4.186 J/g°C, initial temperature = 20°C) is mixed with an unknown mass of iron (specific heat = 0.444 J/gºC, initial temperature 500°C). When equilibrium is reached,The answer for this would be 69.6

You use q = mcΔT, but you assume aluminum = water and crack for This the final temperature.

We need to look up heat values (c) for aluminum and h20. This will uses 0.901 for aluminum and 4.18 use water

: (10)(130 - T)(0.901) = (200.0)(T - 25 (6)

Hence, The answer for this would be 69.6.  

To learn more about  specific heat click here:

https://brainly.com/question/1747943

#SPJ2

Answer:

its ionic

Explanation:

Answer: [tex]K_{eq}[/tex] at  the temperature of the experiment is 0.56.

Explanation:

Moles of  [tex]CO[/tex] = 0.35 mole

Moles of  [tex]H_2O[/tex] = 0.40 mole

Volume of solution = 1.00 L

Initial concentration of [tex]CO[/tex] = [tex]\frac{0.35mol}{1.00L}=0.35M[/tex]

Initial concentration of [tex]H_2O[/tex] = [tex]\frac{0.40mol}{1.00L}=0.40M[/tex]

Equilibrium concentration of [tex]CO[/tex] = [tex]\frac{0.19mol}{1.00L}=0.19M[/tex]

The given balanced equilibrium reaction is,

                      [tex]CO(g)+H_2O(g)\rightleftharpoons CO_2(g)+H_2(g)[/tex]

Initial conc.          0.35 M         0.40 M                  0 M        0M

    At eqm. conc.     (0.35-x) M   (0.40-x) M   (x) M      (x) M

Given:  (0.35-x) = 0.19

x= 0.16 M

The expression for equilibrium constant for this reaction will be,

[tex]K_{eq}=\frac{[CO_2]\times [H_2]}{[CO]\times [H_2O]}[/tex]  

Now put all the given values in this expression, we get :

[tex]K_{eq}=\frac{0.16\times 0.16}{(0.35-0.16)\times (0.40-0.16)}[/tex]

[tex]K_{eq}=\frac{0.16\times 0.16}{(0.19)\times (0.24)}=0.56[/tex]

Thus [tex]K_{eq}[/tex] at  the temperature of the experiment is 0.56.

Answer:

Measure 2.47 mL of the stock solution (i.e 0.0405 mM) and dilute it to the 100 mL mark with water

Explanation:

To make 100 mL of 0.001 mM solution from 0.0405mM solution, we need to determine the volume of 0.0405mM solution needed. This can be obtained as follow:

Molarity of stock (M₁) = 0.0405 mM

Volume of diluted (V₂) = 100 mL

Molarity of diluted solution (M₂) = 0.001 mM

Volume of stock solution needed (V₁) =?

M₁V₁ = M₂V₂

0.0405 × V₁ = 0.001 × 100

0.0405 × V₁ = 0.1

Divide both side by 0.0405

V₁ = 0.1 / 0.0405

V₁ = 2.47 mL

Therefore, to make 100 mL of 0.001 mM solution from 0.0405mM solution, measure 2.47 mL of the stock solution (i.e 0.0405 mM) and dilute it to the 100 mL mark with water.

Solution :

Given :

Hydrogen iodide decomposes to hydrogen and iodine gas

    [tex]$2 HI \ \ \ \Leftrightarrow \ \ \ \ H_2 \ \ \\ + \ \ I_2 $[/tex]

I    0.148            0          0

C     -2a           +a          +a

E  0.148-2a      a            a

We know

[tex]$k_p=\frac{P(H_2)P(I_2)}{P(HI)^2}$[/tex]

[tex]$0.016=\frac{a^2}{(0.148-2a)^2}$[/tex]

[tex]$0.016^{1/2}=\frac{a}{0.148-2a}$[/tex]

[tex]$0.12649=\frac{a}{0.148-2a}$[/tex]

0.0187 = 1.2529 a

a = 0.0149

Therefore

P(HI) = 0.148 - 2a

        = 0.148 - 2(0.0149)

        = 0.1182 atm

P([tex]$H_2$[/tex]) =  a

        = 0.0149 atm

P([tex]$I_2$[/tex]) =  a

        = 0.0149 atm

Answer:

Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons

Answer:

chlorine ~ 30%

zinc ~ 28%

oxygen ~ 41%

Explanation:

Answer:

The heat of reaction is the energy that is released or absorbed when chemicals are transformed in a chemical reaction. It describes the change of the energy content when reactants are converted into products.

Explanation:

Yeah, that would confuse me a bit but then you read it and then you will get that answer above! Have a great rest of your day!

Answer:

1. 1.33 gram of carbon

2. 2.38g of carbon dioxide

Explanation:

From the given information:

Total amount of CO₂ = 4.86 grams

Atomic mass of C = 12 g/mole

molar mass of CO₂ = 44 g/mole

∴

The mass of the Carbon (C) in grams is:

[tex]= Total\ amount \ of \ CO_2 \times \dfrac{12 \ g/mol}{44 \ g/mol}[/tex]

[tex]= 4.86 \ g \times \dfrac{12 \ g/mol}{44 \ g/mol}[/tex]

= 1.33 gram of carbon

2.

Here, the total amount of CO₂ = unknown

Atomic mass of O₂ = 32 g/mole

molar mass of CO₂ = 44 g/mole

amount of oxygen = 1.73 g

∴

The mass of CO₂ = [tex]Total \ amount \ of \ O_2 \times \dfrac{44 \ g/mol}{32\ g/mol}[/tex]

[tex]=1.73 \times \dfrac{44 \ g/mol}{32\ g/mol}[/tex]

= 2.38 g of carbon dioxide

Explanation:

Intermolecular forces hold multiple molecules together and determine many of a substance's properties. All of the attractive forces between neutral atoms and molecules are known as van der Waals forces, although they are usually referred to more informally as intermolecular attraction.

Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions ). These forces are weak compared to the intramolecular forces, such as the covalent or ionic bonds between atoms in a molecule.

Answer:

evaporation is the process

Answer:

Explanation:

Evaporation is the process of becoming a vapor. The process of extracting moisture as by heat.

Evaporation is the process of change from a liquid to a gas at temperatures below the boiling point.

Therefore, the final answer is evaporation.

Answer:

What is the question your asking?

Explanation:

All atoms of the same element have the same properties.

Answer:

I think B

Explanation:

There are more negative ions than positive ions

Answer:

one parent

Explanation:

As one parent cell divides it into two daughter cells and so on.

Answer:

milliliters

Explanation:

Is going to be milliliters because in the metric system of measurement,the most common unit of volume are milliliters and liters

Answer:

Gases we Breathe Out

It is the same air that we inhale. ... The amount of inhaled air contains 21% of oxygen and 0.04% of carbon dioxide, while the air we breathe out contains 16.4% of oxygen and 4.4% of carbon dioxide.

Answer:

Inhaled air is by volume 78% nitrogen, 20.95% oxygen and small amounts of other gases including argon, carbon dioxide, neon, helium, and hydrogen. The gas exhaled is 4% to 5% by volume of carbon dioxide, about a 100 fold increase over the inhaled amount.

Answer:

D. 331 mm Hg

Explanation:

We can solve this problem by keeping in mind the law of partial pressures, which states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of its components.

In other words:

We input the given data:

And calculate the pressure of the nitrogen:

Answer: The mass in grams of potassium chloride required to prepare this solution is 1.862 grams

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]

where,

n = moles of solute

[tex]V_s[/tex] = volume of solution in ml

moles of [tex]KCl[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{xg}{74.5g/mol}[/tex]

Now put all the given values in the formula of molality, we get

[tex]0.100=\frac{x\times 1000}{74.5g/mol\times 250.0ml}[/tex]

[tex]x=1.862g[/tex]

Therefore, the mass in grams of potassium chloride required to prepare this solution is 1.862 grams

Answer: 41.0

Explanation: When you multiply the two numbers you get 41 but you need to have the same amount of significant numbers as the number in the problem with the least significant numbers. I hope this helps

Answer:

600

Explanation:

there's 1 mole in every nitroglycerin

I think

Answer:

six cookies?(1 cal _4.184 j; ALSO: 1 Calorie -1 kilocalorie)

Answer:

I would put the final answer choice: "Scientists must first develop certain technologies before missions can be completed"

Explanation:

The first option is partially true, but we have ways around it.

The second option is straight-up false.

The third option doesn't make much sense, how can one work with technology that will be developed in the future and doesn't yet exist?

Therefore, the fourth option is the best.

Hope this helps

-cyber