The half life of potassium 40 is approximately 1.25 billion years. An igneous rock is found to contain about 1/4 of its original mass of potassium 40. The approximate age of the rock is _____ billion years.

Answers

Answer 1

Answer:

2.5 billion years

Explanation:


Related Questions

Scientific notation of 0.00003

Answers

0.00003 in scientific notation would be 3 × 10⁻⁵.

The scientific notation of a number is represented as a coefficient multiplied by 10 raised to an appropriate exponent.  0.00003 can be expressed in scientific notation as [tex]3\times 10 ^{-5}[/tex].

Scientific notation is a simple and standardised approach to express extremely big or extremely small numbers. Its foundation is the idea that a number can be expressed as a coefficient times a power of 10. The exponent indicates how many places the decimal point must be moved to get the original value, while the coefficient is normally an integer between 1 and 10 (inclusive of 1 but exclusive of 10). To write 0.00003 in scientific notation, we need to move the decimal point five places to the right to make the coefficient between 1 and 10. 0.00003 can be expressed in scientific notation as [tex]3\times 10 ^{-5}[/tex].

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Is my sister bad or good.

Answers

Answer:

decent

Explanation:

PLEASE ANSWER!!!!!!!! WILL MARK BRAILIEST

Answers

9.Pubchem
10.Oxygen
11. Selenium fluoride
12. Disilicon Hexabromide
13. sulfur tetrachloride
14.Methane
15.diboron silicide
16. Nitrogen trifluoride

PLEASE GIVE ME BRAINLIEST!

What do plants do that requires Energy?

Answers

Answer:

Photosynthesis

Explanation:

Photosynthesis uses energy from light to convert water and carbon dioxide molecules into glucose (sugar molecule) and oxygen. The oxygen is released, or “exhaled”, from leaves while the energy contained within glucose molecules is used throughout the plant for growth, flower formation, and fruit development.

In any engineering design problem, the first step is to understand the problem and identify one or more possible solutions. In this task, you’ll analyze the problems you face as the chemical engineer challenged with setting up the ammonia-making process. Recall the chemical equation for producing ammonia:

N2 + 3H2 ⇌ 2NH3 + energy

1.Explain the problem surrounding the ammonia-making process in terms of chemical equilibrium.

Answers

Answer:

Explanation:

About 2,070 results (0.60 seconds)  

Answer is: at lower temperatures the reaction rate would decrease. The lower is the temperature, the slower the reaction becomes. ... Because this is exothermic reaction (enthalpy is less than zero), at lower temperatures, the equilibrium is in favor of ammonia, but the reaction doesn't proceed at a detectable rate.

Hi,

let us go through the question again

N2 + 3H2 ⇌ 2NH3 + energy  

Explain the problem surrounding the ammonia-making process in terms of chemical equilibrium.

So I would approach this question on the basis of effect of each of the reactants and products concentration on the equilibrium synthesis of ammonia.

If the concentration of any reactant is increased, the yield of ammonia is increased.

If the concentration of ammonia is reduced by removing it as it forms, the yield will as well be increased.

This reaction also yields heat meaning it is an exothermic reaction, so when we increase the temperature, the yield will be reduced. Hence it is favored by low temperature.

plssss show your work will mark the brainliest

Answers

Answer:

135.16 mL

Explanation:

From the question,

Applying,

PV/T = P'V'/T'.................... Equation 1

Where P = Initial pressure of the gas, V = Initial volume of the gas, T = Initial Temperature of the gas in Kelvin, P' = Final pressure of the gas, V' = Final Volume of the gas, T' = Final temperature of the gas in Kelvin.

Make V' the subject of the equation

V' = PVT'/TP'................... Equation 2

Given: P = 600 torr, V = 115 mL, T = 50 °C = (50+273) K = 323 K, T' = 75 °C = (75+273) K = 348 K, P' = 550 torr

Substitute these values into equation 2

V' = (600×115×348)/(323×550)

V' = 24012000/117650

V' = 135.16 mL

Please please please please please please help me a b c or d

Answers

Answer:

the answer for this one is the distance the car is driven

Water circulates through Earth's water cycle by changing its _____.
A. state
B. acidity
C. turbidity
D. composition
PLsss I need answers T-T

Answers

Water moved through the water cycle by changing its state. Think, for example, of water evaporating (liquid to gas), snow sublimating (solid to gas) or melting (solid to liquid), rain (gas to liquid), sleet (liquid to solid), or snow (gas to solid).

The answer would thus be A.
A would be your answer.

What volume (in liters, at 253 K and 6.54 atm) of chlorine gas is required to react with 7.89 g of P? 2P(s) + 5Cl2(g) → 5PCl5(s)

Answers

Answer:

7.89 grams of phosphorus reacts with 45.15 grams of chlorine

Explanation:

For reacting with 2 mole of P react with 5 mole of Cl2 gas

Molecular weight of phosphorus = 30.97

Molecular weight of 2 mole of phosphorus = 2 * 30.97 = 61.94 grams

Molecular weight of Chlorine molecule = 70.9 grams

Weight of 5 moles of Chlorine molecule = 5 * 70.9 grams = 354.5 grams

61.94 grams of phosphorus reacts with 354.5 grams of chlorine

7.89 grams of phosphorus reacts with 354.5/61.94 * 7.89  grams of chlorine

7.89 grams of phosphorus reacts with 45.15 grams of chlorine

What are these means in Periodic Table;
Group
Period
Block

Answers

1. Group: Groups shows the number of valence electrons and are shown in columns on the periodic table.

2. Period: Periods show the number of energy levels each element has and are shown in rows on the periodic table (up and down).

3. Blocks are show the amount of orbitals each element has. There is an s block, d block, p block, and f block.

How many grams of 02 will be consumed?

23.36 g 02
11.68 g 02

Answers

Hahahahahabwbwbwbbwwb

PLZ HELP ME!!!! I will give brainlist
1. When water evaporates, the water _____ energy. This is an example of an _____ reaction.
Select one:
a. releases, endothermic
b. absorbs, endothermic
c. absorbs, exothermic

2. Which of the following is an example of increasing entropy?
Select one:
a. a solution becomes more dilute
b. a solute crystallizes
c. total number of product molecules is less than the reactant molecules

Answers

Answer:

For 1, your answer is b. absorbs, endothermic. For 2, your answer is a. a solution becomes more dilute.

Explanation:

I took the test.

If 20% of the nucleotides in a DNA molecule are adenine, what percentage of each of the other three bases would be found in this molecule and explain the answer

This is known as _______________________ rules

please i need help thank you

Answers

What he said is correct!!

Which of the following elements has the largest atomic number?


O tellurium (Te)
lodine (0)
Otin (5)
O antimoney (5b)

Answers

tellurium is the correct answer

Answer:

iodine is 53

tellurium is 52

antimony is 51

Otin Is 50

Explanation:

please help its due tonight!!! also no links allowed.

When 28,242 J are transferred to a water sample, it's temperature increases from 18⁰C to 63⁰C. Determine the mass of the water sample.

Answers

Answer:

149.79 grams.

Explanation:

Formula

Joules = m * c * delta (t)

Givens

J = 28242

m = ?

c = 4.19

Δt = 63 - 18 = 45

Solution

28242 = m * 4.19 * 45

28242 = m * 188.55

m = 28242 / 188.55

m = 149.79

Just do £.15 breakfast

The Himalayan balsam plant makes seeds in pods and releases them when it is ready, while the Surinam toad absorbs its eggs into its own back until they are ready to come out. How are the adaptations of the balsam and the toad similar?

A: They are behaviors that allow the plant and the animal to reproduce through shorter life cycles.

B: They are behaviors that protect the plant and the animal from predators.

C: They are life cycle differences that protect the offspring and help them to survive.

D: They are physical characteristics that allow the offspring to survive in cold weather conditions.

Answers

Answer:a

Explanation:

Answer:

A

Explanation:

How many joules of heat are required to raise the temperature of 320.0 grams of water from 24.2°C to 50.8°C? Heat capacity of water is 4.2 J/g°C.

Answers

Answer:

35750.4 Joules

Explanation:

Using the formula as follows;

Q = m × c × ∆T

Where;

Q = amount of heat (joules)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

According to the provided information,

mass (m) = 320.0 grams

c = 4.2 J/g°C

∆T = (50.8°C - 24.2°C) = 26.6°C

Q = ?

Using; Q = m × c × ∆T

Q = 320 × 4.2 × 26.6

Q = 35750.4 J

What is the pH of a 1.0 L buffer made with 0.300 mol of HF (Ka = 6.8 × 10⁻⁴) and 0.200 mol of NaF to which 0.150 mol of HCl were added

Answers

Answer:

pH = 2.21

Explanation:

Hello there!

In this case, according to the reaction between NaF and HCl as the latter is added to the buffer:

[tex]NaF+HCl\rightarrow NaCl+HF[/tex]

It is possible for us to see how more HF is formed as HCl is added and therefore, the capacity of this HF/NaF-buffer is diminished as it turns acid. Therefore, it turns out feasible for us to calculate the consumed moles of NaF and the produced moles of HF due to the change in moles induced by HCl:

[tex]n_{HF}^{new}=0.300mol+0.150mol=0.450mol\\\\n_{NaF}^{new}=0.200mol-0.150mol=0.050mol[/tex]

Next, we calculate the resulting concentrations to further apply the Henderson-Hasselbach equation:

[tex][HF]=\frac{0.450mol}{1.0L} =0.450M[/tex]

[tex][NaF]=\frac{0.050mol}{1.0L} =0.050M[/tex]

Now, calculated the pKa of HF:

[tex]pKa=-log(6.8x10^{-4})=3.17[/tex]

We can proceed to the HH equation:

[tex]pH=pKa+log(\frac{[NaF]}{[HF]} )\\\\pH=3.17+log(\frac{0.05M}{0.45M} )\\\\pH=2.21[/tex]

Best regards!

pH is the measure of the hydrogen or hydronium ion concentration in an aqueous solution. The pH of the buffer made with HF and NaF is 2.21.

What is pH?

pH is the measure of the acidic or the basic content in a solution that can be given by the hydrogen or the hydroxide concentration.

The reaction can be shown as,

[tex]\rm NaF + HCl \rightarrow NaCl + HF[/tex]

New moles of HF is 0.300 + 0.150 = 0.450 moles and new moles of NaF is 0.200 - 0.150 = 0.050 moles.

The concentration is calculated by the Henderson-Hasselbach equation:

[tex]\rm [HF] = \dfrac{0.450 \;\rm mol}{1.0 \;\rm L} = 0.450 \;\rm M[/tex]

And,

[tex]\rm [NaF] = \dfrac{0.050\;\rm mol}{1.0 \;\rm L} = 0.050\;\rm M[/tex]

pKa of hydrogen fluoride is calculated as:

[tex]\rm pKa = - log (6.8 \times 10^{-4}) = 3.17[/tex]

The pH from the pKa can be calculated as:

[tex]\begin{aligned}\rm pH &=\rm pKa + log (\dfrac{[NaF]}{[HF]})\\\\&= 3.17 + \rm log (\dfrac{0.05}{0.45})\\\\&= 2.21\end{aligned}[/tex]

Therefore, the pH is 2.21.

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If the prescribed dosage of milk of magnesia Mg(OH)2 is 3.5 moles, how many grams
would you need to take? Round to the nearest tenth (one digit after the decimal).
A. 92.1 g
B. 204.2g
C. 157.2 g
D. None of the above

Answers

Answer:

B

Explanation:

1 mole is equal to 58.31968 grams.

so 3.5 moles equal to answer choice B

In the above equation how many moles of NO can be made when 43 moles of HNO3 are consumed?

Answers

Answer:

rn4y8rg7348y0rp934nrf3

efjewhrf8h934hfr84398wgfyu8o

Explanation:

fe8u34h4n3urhu93q4pirnpqr34uwbry8439br8u3i2rpi34ofreuebue rf ef erf3rw  wg

When hydrogen and fluorine bond, the fluorine atom's electron configuration most resembles which element? A. nitrogen B. helium C. oxygen D. neon

Answers

Answer:

D. neon.

Explanation:

Hello there!

In this case, according to the following bonding:

[tex]H-F[/tex]

It is possible to bear to mind the fact that hydrogen has one valence electron whereas fluorine has seven. Moreover, once they bond, we understand fluorine takes the only hydrogen's valence electron to attain the electron configuration of the former's contiguous noble gas which is D. neon.

Best regards!

which scale is most precise?

which scale is most accurate?

Answers

I think both answers are scale 1.

It’s most precise bc it goes to thousandths but it’s also closest to 1 making it most accurate.

What is the volume, in liters, of 2.75 grams of fluorine gas at 35.0°C and 4.55 atm pressure?

Answers

use PV=nRT
•n =mass in grams of flourine /molar mass
• R=0.0821
•temp must be in kelvins (+273)
volume will be in dm3 which is equals to litres


try it by yourself
good luck

The volume (in litres) of 2.75 g of fluorine gas at 35 °C and 4.55 atm is 0.402 L

How to determine the mole of fluorine gasMass of F₂ = 2.75 gMolar mass of F₂ = 2 × 19 = 38 g/mol Mole of F₂ =?

Mole = mass / molar mass

Mole of F₂ = 2.75 / 38

Mole of F₂ = 0.0724 mole

How to determine the volume Temperature (T) = 35 °C = 35 +  273 = 308 KPressure (P) = 4.55 atmGas constant (R) = 0.0821 atm.L/Kmol Number of mole (n) = 0.0724 moleVolume (V) =?

Using the ideal gas equation, the volume of the gas can be obtained as follow:

PV = nRT

Divide both side by P

V = nRT / P

V = ( 0.0724 × 0.0821 × 308) / 4.55

V = 0.402 L

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A covalent bond is formed when two atoms reach a stable state that balances:

MARK TWO RESPONSES

A
the repulsion between the nucleus protons of one atom to the electrons of the other atom


B
the attraction between the nucleus of one atom to the electrons of the other atom


C
the attraction between the two nuclei of the atoms, which both contain protons


D
the repulsion between the two nuclei of the atoms, which both contain protons

Answers

Answer:

B and I think A but you may want a secon opinion on that

Explanation:

I know that electrons are shared with covalent bonds so I assume the 2 answers are the ones with electrons it them

B and A

Explanation : ^

Question 16 of 33
Which sublevels contain valence electrons in an atom of nitrogen (N)?
The Periodic Table
A. 2s and 2p
B. 2s only
C. 3p only
O D. 2s and 3p

Answers

I think the answer is A

This worm infects humans by getting into the blood stream. It gets a
warm, safe home in the blood stream. Humans are harmed because they
may go blind or have other complications due to the parasite.
A. Mutualism
B. Commensalism
C. Parasitism

Answers

Pretty sure it’s C- hope this helps❤️

For the reaction 2H2 + O2 --> 2H2O, how many grams of oxygen are needed to react 3 moles of hydrogen?

Answers

Answer:

48 grams

Explanation:

The chemical equation for the reaction is the following:

2 H₂ + O₂ → 2 H₂O

That means that 2 moles of H₂ react with 1 mol of O₂ to produce 2 moles of H₂O. We convert the moles of oxygen (O₂) by using the molecular weight (MW) as follows:

MW(O₂) = 16 g/mol x 2 = 32 g/mol

mass of O₂ = 1 mol x 32 g/mol = 32 g

So, we have the following stoichiometric ratio: 32 g O₂/2 moles H₂. We have 3 moles of hydrogen (H₂), so we multiply the moles by the stoichiometric ratio to calculate how many grams are needed:

3 moles H₂ x 32 g O₂/2 moles H₂ = 48 g O₂

Therefore, 48 grams of O₂ are needed to react with 3 moles of H₂.

State and explain the three basic properties of element​

Answers

Answer: Some are solid, some are gaseous, a few are liquid. Some are metallic: they have a peculiar lustre; some are coloured (like sulfur) or colourless. Some have a low density; some have a high density. Some are malleable and ductile; some are brittle. Some conduct electricity and heat well; some don’t.

Many metals tend to have structural uses. Nonmetallic elements less so.

Metals tend to have crystal forms featuring close-packed centro-symmetrical structures. Nonmetallic elements tend to have crystal structures featuring more open and directionally packed structures.

Some are especially toxic; some are essential to life; some are both depending on exposure level.

Most are stable; some are less so.

Some elements are highly reactive; some are almost inert (helium, neon, and argon may be completely inert in ambient conditions).

Many metals have basic oxides; quite a few oxides of nonmetallic elements form acids when they are dissolved in water. Some elements can go both ways.

There are many generalisations you can make about metallic and nonmetallic elements, and quite a few exceptions at the margins.

Explanation:

Given :-

State and explain the three basic properties of element.

Answer :-

Some properties of an element can be observed only in a collection of atoms or molecules of the element. These properties include color, density, melting point, boiling point, and thermal and electrical conductivity.

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Answered by - ItzMaster

50 POINTS

Gizmos Moles Activity - chemistry

can someone please help me out

Answers

there is how I would answer it.

The planet Mercury takes 176 days to do one spin around its pole. Compared to the Earth,

would the Sun appear to move more quickly across Mercury's sky or more slowly? Why?

Thank you who ever help me

Answers

Answer:

The sun would appear to move more slowly across Mercury's sky.

Explanation:

This is because, the time it takes to do one spin or revolution on Mercury is 176 days (which is its period), whereas, the time it takes to do one spin or revolution on the Earth is 1 day.

Since the angular speed ω = 2π/T where T = period

So on  Mercury, T' = 176days = 176 days × 24 hr/day × 60 min/hr × 60 s/min = ‭15,206,400‬ s

So, ω' = 2π/T'

= 2π/15,206,400‬ s

= 4.132 × 10⁻⁷ rad/s

So on  Earth, T" = 1 day = 1 day × 24 hr/day × 60 min/hr × 60 s/min = ‭‭86,400‬ s

So, ω" = 2π/T"

= 2π/86,400‬ s

= 7.272 × 10⁻⁵ rad/s

Since ω' = 4.132 × 10⁻⁷ rad/s << ω" = 7.272 × 10⁻⁵ rad/s, the sun would appear to move more slowly across Mercury's sky.

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