Since the replication crisis, many practices have been implemented to improve research and promote –, or the practice of sharing data and materials so they can be reviewed and replicated by other researchers. One of these practices involves submitting the proposed methods and analysis plan to journals in advance for approval or –. This practice allows scientific journals to approve experiments before they are done, with the guarantee that any finding will be published regardless of whether or not it is significant. This process also prevents researchers from –, or creating theories or hypotheses that explain the results of a study after the data has been collected.

Answer:

carbon-12

Explanation:

carbon 6/12 isotope has 6 neutrones and it is considered as a metal.

Answer:

1 g

Explanation:

The following data were obtained from the question:

Original amount (N₀) = 32 g

Time (t) = 71.5 days

Half-life of phosphorus (t½) = 14.3 days

Amount remaining (N) =?

Next, we shall determine the rate of disintegration. This can be obtained as follow:

Half-life of phosphorus (t½) = 14.3 days

Decay constant (K) =?

K = 0.693 / t½

K = 0.693 / 14.3

K = 0.0485 /day

Finally, we shall determine the amount remaining as illustrated below:

Original amount (N₀) = 32 g

Time (t) = 71.5 days

Decay constant (K) = 0.0485 /day

Amount remaining (N) =?

Log (N₀/N) = Kt/2.303

Log (32/N) = 0.0485 × 71.5 / 2.303

Log (32/N) = 3.46775 / 2.303

Log (32/N) = 1.5058

Take the antilog of 1.5058

32/N = antilog (1.5058)

32/N = 32.05

Cross multiply

32 = N × 32.05

Divide both side by 32.05

N = 32 / 32.05

N = 0.998 ≈ 1 g

Thus, the amount remaining after 71.5 days is approximately 1 g.

The half-life of a radioactive substance refers to the time taken for the substance to Decay to half of its initial size. Hence, the mass of the substance left after 71.5 days is 1 gram.

After 14.3 days ;

After 14.3 × 2 = 28.6 days :

After 14.3 × 3 days = 42.9 days :

After 14.3 × 4 days = 57.2 days :

After 14.3 × 5 days = 71.5 days :

Hence, the mass of the sample left after 71.5 days would be 1 gram.

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Answer:

The screw with 10 wraps is the correct answer

Explanation:

The screw with 6 wraps would create a strong hold.

The strongest member of the family of wood screws is a lag screw. It is a reliable and sturdy fastener that frequently has a square head or an externally powered hex drive.

In general, lag screws are significantly stronger and heavier than standard wood screws. They have a tapered point and coarse threads.

Thus, The screw with 6 wraps would create a strong hold.

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# SPJ5

Answer:

Put sand in one cup and water in the other. Put two heat lamps at equal height and under each one put the water and sand, this must be done at the same exact time. Set a timer for 5, then 10, then 15, and so forth minutes. Each time measure the temperature of each with the thermometers and write the down. Have a certain temperature you want them to get to and see which gets to it quicker. Then set a new temp 3 times to see if the answer is consistent.

Explanation:

Doing this would test whether land or water heats quicker.

Answer:

heat lamps

Explanation:

Answer:

A.) It cannot be quickly replaced.

Explanation:

Aluminum is extremely useful to humans but is semi-difficult to produce. Because of this, your answer will be numero uno. (Or A.)

Answer:

6 hours

Explanation:

If it is traveling at 50mph and needs to reah 300 miles, to figure this problem out you would want to divide 300 by 50 to get 6 hours. So it will take six hours until the car travels 300 miles

Hope this helps.

Answer: A car travels at a rate of 50 miles per hour. how long will it take the car to travel 300 miles?

Explanation: .

Applying the distance formula:

d = rt

where

d is distance (300 miles)

r is rate (50 mph)

t is time (hours)

.

300 = 30t

300/30 = t

10 hours = t

Answer:

Increase

Explanation:

Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

Answer:

C. CH₄ is less than NH₃ because the NH bond is more polar than the CH bond

Explanation:

The intermolecular forces between ammonia is far stronger than for methane. Between the molecules of ammonia we have the presence of hydrogen bonds. This bond is absent in methane.

Hydrogen bonds are one of the strongest intermolecular forces. It is as a result of the electrostatic attraction between the hydrogen atom of one molecule and the electronegative atom N, O and F of another molecule.

The strength of the hydrogen bond depends on the electronegativity of the combining atoms.

Answer:

The tempreature???

Explanation:

Colder tempreatures lead to a slower chemical reaction and warmer tempreatures lead to a faster  chemical reaction.

Answer:

Greater

Greater

Explanation:

The amplitude of a wave is the height of the wave or the vertical displacement of the wave motion. We determine a wave amplitude usually by looking at the graph of the wave.

Amplitude is directly proportional to the energy of a wave. The higher the amplitude of a wave, the more its energy.

Frequency is the number of waves that passes a point at a particular instance of time. It is also directly proportional to the energy carried by a wave. The higher the frequency of a wave, the greater its energy.

Answer:

fewer collisions occur between particles or lowering the temperature

Explanation:

Answer:

1.181 × 10²⁴ molecules CO₂

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

86.34 g CO₂

Step 2: Identify Conversion

Avogadro's Number

Molar Mass of C - 12.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of CO₂ - 12.01 + 2(16.00) = 44.01 g/mol

Step 3: Convert

[tex]86.34 \ g \ CO_2(\frac{1 \ mol \ CO_2}{44.01 \ g \ CO_2} )(\frac{6.022 \cdot 10^{23} \ molecules \ CO_2}{1 \ mol \ CO_2} )[/tex] = 1.18141 × 10²⁴ molecules CO₂

Step 4: Check

We are given 4 sig figs. Follow sig fig rules and round.

1.18141 × 10²⁴ molecules CO₂ ≈ 1.181 × 10²⁴ molecules CO₂

Answer:

b

Explanation:

i looked it up on Google

Answer:

The reaction produces insoluble lead (II) sulphate which coats the surface of lead (II) nitrate  [Pb(NO3)]

% m/v of the solution = 0.2%m/v

[tex]\tt Percent~m/v=\dfrac{mass~solute(g)}{volume~solution(ml)}\times 100\%[/tex]

or

% m/v = g solute / 100 ml solution

Concentration : 2 g sodium borate / L water

For 10 L⇒20 g Sodium borate

[tex]\tt \%m/v=\dfrac{20~g}{10,000~ml}\times 100\%\\\\\%m/v=0.2\%[/tex]

Answer:

The mass number of an isotope is indicated in the name of the isotope by writing the name of the element followed by a hyphen and the mass number.

Explanation:

Examples include carbon-14, uranium-235, and oxygen-17.

Answer:

A change in the shape of a substance

Explanation:

Because when ths shape of a sunstance changes , its physical appearance changes .A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

1. ₉¹⁹F

2. Mg(OH)₂

3. 2H₂ + O₂ ⇒ 2H₂O

1. Fluorine, atomic number : 9 , mass number = 19

Symbol : ₉¹⁹F

protons=electrons=atomic number = 9

neutrons = mass number - atomic mass

[tex]\tt n=19-9=10[/tex]

Configuration : [He] 2s² 2p⁵

2. Magnesium hydroxide is an ionic compound and is a strong base consisting of 2 ions:

Positive ion: Magnesium: Mg²⁺

negative ion: Hydroxide: OH⁻

The charges of the two are crossed, so that the compound becomes:

Mg(OH)₂

3. Reaction :

H₂ + O₂ --------> H₂O

give coefficient :

aH₂ + bO₂ --------> H₂O

H, left = 2a, right 2⇒2a=2⇒a=1

O, left = 2b, right 1⇒2b=1⇒b=0.5

Reaction becomes :

H₂ + 0.5O₂ --------> H₂O x 2

2H₂ + O₂ --------> 2H₂O

Ionic compounds are formed from metal and non-metal elements

The chemical formula of compounds (especially ionic compounds) can be determined from the charge of each ion.

Determination of the ionic charge of the constituent elements of the compound can be seen from the electron configuration to achieve stability according to the octet rule

The charge of each ion will be crossed in the compound

Aluminum bromide

Al³⁺ + Br⁻ ⇒ AlBr₃

Magnesium bromide

Mg²⁺ + Br⁻ ⇒ MgBr₂

Sodium sulfide

Na⁺ + S²⁻ ⇒ Na₂S

Sodium nitride

Na⁺ + N³⁻ ⇒ Na₃N

Explanation:

Glass is not a liquid in the strictest sense of the word. But it is also not a standard solid. The chemistry of glass is complex and research is ongoing, but the current consensus is that glass is a phase of matter all its own, known as an "amorphous solid". Scientists refer to any amorphous solid as a "glass". Glass transitions are highly complex and cannot be treated in the same way as traditional phase transitions.

Answer:

It's a liquid state before its cooled.

The chemical equation is said to be balanced if the number of atoms in the reactants and products is the same

Equation balanced ⇒ total number of atoms in reactants(on the left)= total number of atoms in products(on the right)

H₂+O₂---> H₂O

Reactants : H₂, O₂

Products : H₂O

not balanced

H₂O₂ ---> H₂O+O₂

Reactants : H₂O₂

Products : H₂O, O₂

not balanced

Na+O₂ ---> Na₂O

Reactants : Na, O₂

Products :  Na₂O

not balanced

N₂+H₂ ---> NH₃

Reactants : N₂, H₂

Products :  NH₃

not balanced

P₄+O₂---> P₄O₁₀

Reactants : P₄, O₂

Products :  P₄O₁₀

not balanced

Fe+H₂O ----> Fe₃O₄ + H₂

Reactants : Fe, H₂O

Products :  Fe₃O₄

not balanced

Answer: Due to the sharing of electrons, they exhibit characteristic physical properties that ... Here, we discuss two classes of compounds based on the bond type that ... Covalent bonds are characterized by the sharing of electrons between two or ... Describe the types of orbital overlap that occur in single, double, and triple bonds

Explanation: That's what I think it is.

Answer:

6.8 mole of O₂

Explanation:

Given expression:

       2H₂   +   O₂   →   2H₂O

Number of moles of H₂ = 13.6moles

Unknown:

Number of moles of O₂  = ?

Solution:

In the given problem, we are to find the number of moles of oxygen gas that will use up 13.6mole of hydrogen gas;

 From the reaction equation;

             2 mole of H₂ will completely react with 1 mole of O₂

         13.6 moles of H₂ will completely be used up by [tex]\frac{13.6}{2}[/tex] mole of  O₂

                                                                                        = 6.8 mole of O₂

Answer:

B - What we change

Explanation:

Dependent Variable - What we measure

Control Variable - what stays the same

Conclusion - what we conclude

Hope this can Help!

:D

Answer:

Explanation:

by stoichiometry

nNH3/2=nH2/3

0.25/2=nH2/3

nH2=0.25×3/2

nH2=0.375 mol

so its 0.38 mol

Answer:

I have this quiz rn I will try 0.38 if it is right I’ll edit this and say that

Explanation:

Answer:

Ca3(PO4)2 and Na

Explanation:

The reaction equation is;

3Ca + 2Na3PO3 -------> Ca3(PO3)2 + 6Na

We must remember that calcium is above sodium in the electrochemical series. This implies that calcium can displace sodium from its solution. Calcium has a reduction potential of -2.87 V while sodium has a reduction potential of -2.71 V. The ion with the more negative reduction potential can easily displace the other in aqueous solution.

This explains why the reaction above is possible.