A radioactive sample is placed in a closed container. Two days later only one-quarter of the sample is still radioactive. What is the half-life of this sample?

Answer:

Mass of hydrogen in 42 gram of J = 8.4

Explanation:

Given:

Amount of compound J = 10 gram

Mass ratio[lithium (Li): Hydrogen (H)] = 8:2

Find:

Mass of hydrogen in 42 gram of J

Computation:

Mass of hydrogen in 10 gram of J = [2 / 10] 10

Mass of hydrogen in 10 gram of J = 2 gram

Mass of hydrogen in 42 gram of J = [2 / 10] 42

Mass of hydrogen in 42 gram of J = 8.4

Answer:

Force is measured in Newtons

Explanation:

To find normal force on an incline, use the equation N = mg cos(x), “m” being the object's mass, “g” being the acceleration of gravity, and “x” being the angle of incline. Then, use a calculator to find the cosine of the angle and write down that value.

The balanced redox reaction equation can be given as;

2BrO2 + 4OH- + N2O4 → 2BrO3- + 2H2O + 2NO2-

Making sure that the number of electrons acquired in the reduction half-reaction equals the number of electrons lost in the oxidation half-reaction is necessary to balance a redox (reduction-oxidation) reaction.

Give each element in the chemical equation an oxidation number. This process aids in identifying how the oxidation states vary throughout the reaction. Find the total redox equation's oxidation half-reaction and reduction half-reaction.

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The mass of the asteroid is C. 1.2 x \(10^{12}\) Kg

To find the mass of the other asteroid, we can rearrange the equation for the gravitational force between two objects:

F = (G * m1 * m2) / \(r^{2}\)

where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the two asteroids, and r is the distance between them.

Given that the distance between the asteroids is 75000 m, the force of gravity between them is 1.14 N, and one asteroid has a mass of 8 x \(10^{7}\) kg, we can substitute these values into the equation and solve for the mass of the other asteroid (m2):

1.14 N = (6.67430 × \(10^{-11}\) N \(m^{2}\)/\(Kg^{2}\) * 8 x \(10^{7}\) kg * \(m2\)) / \((75000 m)^{2}\)

Simplifying and solving the equation, we find that the mass of the other asteroid (m2) is approximately 1.2 x \(10^{12}\) kg. Therefore, Option C is correct.

The question was incomplete. find the full content below:

Two asteroids are 75000 m apart one has a mass of 8 x \(10^{7}\) kg if the force of gravity between them is 1.14 what is the mass of the asteroid

A. 3.4 x \(10^{11}\) kg

B. 8.3 x \(10^{12}\) kg

C. 1.2 x \(10^{12}\) kg

D. 1.2 x \(10^{10}\) kg

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Paulo  needs to use a phase diagram to show how much stable each of the various phases of water is.

The phase diagram could be used to obtain the changes in a substance at different phases of matter. We know that water could exist as solid, liquid or gas. The state in which the water is a function of the pressure and the temperature of the system.

The phase diagram could be used to see the various conditions of temperature and pressure where we can trace to the liquid, solid and gaseous phases of the substance that is under study. On this phase diagram, we can also locate the triple point of water.

Given that the pressure and the temperature changes of water could be shown on a phase diagram, it then follows that Paulo  needs to use a phase diagram to show the various phases of water.

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Answer:

ATP

Explanation :

Because the energy is released during the process of glycolysis in cellular respiration and then the molecule is captured by the energy carrying molecule which is the ATP (adenosine triphosphate).

1.267 x 10 ^ 24 is the total number of atoms

Answer:

Zero with the subscripts, +2 without them.

Explanation:

Hello!

In this case, since we consider that two silicon are bonded with four oxygen atoms to form silicon oxide according to the following chemical equation:

\(Si^{4+}+O^{2-}\rightarrow Si_2O_4\)

It is also possible to realize it can be simplified to obtain:

\(SiO_2\)

Which means that the total charge with the subscripts is zero, and without the subscripts +2 (+4-2).

Best regards!

The probability of the flowers being green (aa) is 2/4 or 1/2 (or 50%).

Alleles are alternative versions of a gene that exist at the same locus (position) on a chromosome. Genes code for specific traits or characteristics, and alleles represent different forms of the same gene that may produce different variations of that trait.

It depends on the genetic makeup of the flowers and the specific breeding pattern.

If we assume that the flowers follow Mendelian inheritance patterns, where each plant has two alleles (versions of a gene), and the A allele is dominant over the a allele (meaning if a plant has at least one A allele, it will have red flowers), then there are three possible genotypes for the flowers:

AA: homozygous dominant, which will produce red flowers

Aa: heterozygous, which will also produce red flowers (since the A allele is dominant)

aa: homozygous recessive, which will produce green flowers

If we don't know the specific genotype of the flowers, we can use the Punnett square to calculate the probability of each genotype. Assuming that the parent flowers are both Aa (heterozygous), the Punnett square would look like this:

     A       a

A  AA     Aa

a  Aa      aa

Each box represents a possible offspring genotype. We can see that there are two boxes that contain the aa genotype (green flowers), out of a total of four boxes. Therefore, the probability of the flowers being green (aa) is 2/4 or 1/2 (or 50%).

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The most recent theory to explain the structure of an atom is thought to be the quantum one. The main difference between the quantum model and the Bohr model is that the later represents the dual nature of an electron as both a wave and a particle, while the former defines the behavior of an electron as a particle.

Therefore , the electron is viewed as a particle with definite orbits around the nucleus in the Bohr Model. The electron is mathematically handled as a wave in the quantum mechanical model. The electron possesses both particle- and wave-like characteristics.

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Answer:

6. 7870 kg/m³ (3 s.f.)

7. 33.4 g (3 s.f.)

8. 12600 kg/m³ (3 s.f.)

Explanation:

6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.

1 kg= 1000g

1m³= 1 ×10⁶ cm³

Mass of iron bar

= 64.2g

= 64.2 ÷1000 kg

= 0.0642 kg

Volume of iron bar

= 8.16 cm³

= 8.16 ÷ 10⁶

\( = 8.16 \times 10^{ - 6} \: kg\)

\(\boxed{density = \frac{mass}{volume} }\)

Density of iron bar

\( = \frac{0.0642}{8.16 \times 10^{ - 6} } \)

= 7870 kg/m³ (3 s.f.)

7.

\(\boxed{mass = density \: \times volume}\)

Mass

= 1.16 ×28.8

= 33.408 g

= 33.4 g (3 s.f.)

8. Volume of brick

= 12 cm³

\( = 12 \times 10^{ - 6} \: m^{3} \\ = 1.2 \times 10^{ - 5} \: m ^{3} \)

Mass of brick

= 151 g

= 151 ÷ 1000 kg

= 0.151 kg

Density of brick

= mass ÷ volume

\( = \frac{0.151} {1.25 \times 10^{ - 5} } \\ = 12600 \: kg/ {m}^{3} \)

(3 s.f.)

The final volume is 30.62L

Volume is the amount of space occupied by a three-dimensional figure as measured in cubic units

Here given data is

NH₄NO₃ = 17.5 g

Concentration = 1.75 M

We have to calculate final volume solution = ?

So Concentration = mass/volume

Volume = concentration × mass

Volume =  1.75 M ×  17.5 g

Volume = 30.62L

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The volume of 0.350 M KOH required to react completely with 13.1 mL of 0.190 M H2SO4 is 14.2 mL.

The balanced chemical equation for the reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH) is:

H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(l)

From the equation, we can see that 1 mole of H2SO4 reacts with 2 moles of KOH. Therefore, we need to determine the number of moles of H2SO4 present in 13.1 mL of 0.190 M solution:

moles of H2SO4 = concentration x volume

= 0.190 M x 0.0131 L

= 0.00249 moles

Since 1 mole of H2SO4 reacts with 2 moles of KOH, we need 2 x 0.00249 = 0.00498 moles of KOH to completely react with the given amount of H2SO4.

To calculate the required volume of 0.350 M KOH, we use the following formula:

moles of solute = concentration x volume of solution

Rearranging the formula to solve for volume, we get:

volume of solution = moles of solute / concentration

Substituting the values, we get:

volume of KOH = moles of KOH / concentration of KOH

= 0.00498 moles / 0.350 M

= 0.0142 L or 14.2 mL

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Answer:

A).

ΔH is positive, Therefore reaction is endothermic

B).

ΔG = ΔH - T∙ΔS

= 98.4 kJ/mol - 300K ∙ 0.09564 kJ/molK

= 69.7 kJ/mol

C).

ΔG is positive, Therefore reaction is non-spontaneous

Explanation:

look i know that its not a drawing but its the best that i can do with what i have. i hope this helps!

Answer:

Empirical formula of a compound means that it provides simplest ratio of whole number.

Explanation:

Mass of boron and chlorine is 9.224% and 90.74%

Helen takes 35 nights to knit a total of 175 centimeters of scarf. Hence, she will take 36 nights to knit 180 centimeters of scarf.

Length is a basic measurement in for an object which is basically taken in meters or centimeters. The basic unit of length in American standard is meters (m) and in CGS system it is centimeters.

It is given that, Helen knit a total of 175 centimeters of a scarf over 35 nights. Then, the length she knit in one nigh is calculated as:

175/35 = 5 cm.

Therefore, the number of nights required to complete 180 cm is :

180 /5 = 36

Thus, she will take 36 nights to knit a total of 180 cm of scarf.

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The statement which gives you enough information to say that the atom is electrically neutral is: The atom has 7 protons and 7 electrons.

To calculate the volume of 0.3000 M NaCl solution that is required to produce 0.1950 moles of NaCl, we can use the formula: moles = Molarity x Volume

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Answer:

In summer, anticyclones bring dry, hot weather. In winter, clear skies may bring cold nights and frost. In cold conditions, anticyclones may also bring fog and mist. This is because the cold forces moisture in the air to condense at low altitudes.

Answer:

an anticyclone is an area of high pressure that brings fine setteled weather. in an anticyclone the air is decending which means it is trapped on the ground and cannot rise, therefore we don't get rain!

Explanation:

Answer:

P6S9

Explanation:

Firstly, let's write the numbers in Latin

1 = mono

2 = di

3 = tri

4 = tetra

5 = penta

6 = hexa

7 = hepta

8 = octa

9 = nona

Secondly, write the symboles of the given elements:

Phosphorus is P

Sulfide is S

Finally, connect the numbers and symbols.

Rule of pronunciation: Number of first element + symbol of first element + number of second element + symbol of second element

P6S9

Please upvote.

Answer:

When magnesium metal burns, magnesium oxide is formed. This substance is known as a metal oxide.

Explanation:

The reaction is represented by the following chemical equation:

2Mg(s) + O2(g) -> 2MgO(s)

ANSWER

The final pressure of the gas is 1350.22 mmHg

STEP-BY-STEP EXPLANATION:

Given information

From the question provided, you were asked to find the final pressure of the gas, hence, we assume that x represents the final pressure of the gas

To find the final pressure of the gas, we need to apply the general gas law

Where,

P1 = initial pressure

V1 = initial volume

T1 = initial temperature

P2 = final pressure

V2 = final volume

T2 = final temperature

The next process is to convert the final and initial temperature from degree Celcius to degree kelvin

The next thing is to substitute the given data into the above formula

Therefore, the final pressure of the gas is 1350.22 mmHg

371.4 g of glucose must be metabolized to produce 223 g of water.

The balanced chemical equation for the complete combustion of glucose is:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

According to the equation, for every 1 mole of glucose consumed, 6 moles of water are produced.

The molar mass of glucose is:

6(12.01 g/mol) + 12(1.01 g/mol) + 6(16.00 g/mol) = 180.18 g/mol

To calculate the mass of glucose required to produce 223 g of water, we need to first convert the mass of water to moles:

223 g / 18.015 g/mol = 12.38 mol H₂O

Now we can use the mole ratio from the balanced equation to calculate the moles of glucose required:

1 mol glucose / 6 mol H₂O = x mol glucose / 12.38 mol H₂O

x = 2.06 mol glucose

Finally, we can calculate the mass of glucose:

mass = moles × molar mass

mass = 2.06 mol × 180.18 g/mol = 371.4 g

Therefore, 371.4 g of glucose must be metabolized to produce 223 g of water.

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The statement that is true about the ionic size of the elements in a group as one moves from bottom to top in that group is as follows: Ionic size decreases from bottom to top within the group (option A).

Periodic table is a tabular chart of the chemical elements according to their atomic numbers so that elements with similar properties are in the same group.

Ionic size increases from top to bottom down a group of elements in the periodic table. From left to right across a period, the ionic size decreases as long as you are comparing all metals or all nonmetals.

In a periodic table while moving down in a group, atoms add an extra shell (number of electrons) due to which the ionic size of elements increases down a group i.e. from top to bottom.

This means that from bottom to top, the ionic size of the elements in the group will decrease.

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The most reactive element based on the given data among the given options is option c) Element J.  

This can be determined based on their placement on the periodic table. The reactivity of an element is dependent on its position on the periodic table, particularly its electron configuration and the number of valence electrons it has. For instance, elements located in the top left corner of the periodic table are typically the most reactive.

They have fewer electrons in their outermost shell and have a tendency to lose them or combine with other elements in order to obtain a full outer shell or achieve stability.In this case, Element J is most likely located in the far left of the periodic table, most likely in the alkali metals group, which contains some of the most reactive metals.

Alkali metals are highly reactive because they only have one valence electron, making it easy for them to give it up and form positive ions. As a result, Element J is the most reactive among the given elements.The correct answer is c.

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Answer:

he correct equilibrium constant expression (Keq) for the given equation is:

Keq = ([HCl]^4 [O2]) / ([Cl2]^2 [H2O]^2)

Where [HCl], [O2], [Cl2], and [H2O] represent the equilibrium concentrations of the respective species in the balanced equation.

Note that the Keq expression includes only the concentrations of the gases in the equilibrium mixture, and the coefficients in the balanced equation are used as exponents to represent the stoichiometry of the reaction.

([HCl]⁴ [O\(_2\)]) / ([Cl\(_2\)]² [H\(_2\)O]²)  is the correct equilibrium constant expression for this equation. The reaction quotient value obtained from the expression describing chemical equilibrium.

The reaction quotient value obtained from the expression describing chemical equilibrium is the equilibrium constant. It is influenced by temperature and ionic strength and is unaffected by the amounts of product and reactant in a solution.

Reactions which attain heterogeneous equilibrium have more than one phase. Typically, only two phases—such as gaseous and liquid phases and solids and liquids—are present. The expression for equilibrium does not include solids.

Keq = ([HCl]⁴ [O\(_2\)]) / ([Cl\(_2\)]² [H\(_2\)O]²)

Therefore, ([HCl]⁴ [O\(_2\)]) / ([Cl\(_2\)]² [H\(_2\)O]²) is the correct equilibrium constant expression for this equation.

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Answer: high pressure, high temperature water extraction

Explanation:

Answer:

C). high pressure, high temperature water extraction

Explanation:

Mendel's first generation pea plants with purple flowers would have had two alleles for flower color.

Alleles are different versions or variants of a gene that occupy the same position, or locus, on a chromosome. Each individual inherits two alleles for each gene, one from each parent, which can be either the same (homozygous) or different (heterozygous). These alleles can have different effects on the organism's phenotype (observable trait) and can be dominant or recessive, with dominant alleles masking the expression of recessive ones. For example, in humans, the gene for eye color has different alleles that produce different colors such as brown, blue, or green. The specific combination of alleles that an individual inherits determines their genotype, which in turn influences their phenotype. The study of alleles and their inheritance patterns is a fundamental concept in genetics and has important applications in fields such as medicine, agriculture, and evolutionary biology.

Here,

However, the specific alleles cannot be determined from this information alone. According to Mendel's laws of inheritance, each individual inherits two alleles for each trait, one from each parent. These alleles can be either the same (homozygous) or different (heterozygous). If the two alleles are different, one may be dominant and determine the organism's phenotype (observable trait), while the other may be recessive and not expressed in the phenotype. In the case of Mendel's purple-flowered pea plants, the specific alleles responsible for the purple flower color would have been determined through further experimentation and analysis.

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Answer:

The rocks that result from these processes often have ribbonlike layers and may have shiny crystals, formed by Metamorphic Rock growing slowly over time, on their surface.

The rocks that result from these processes often have ribbonlike layers and may have shiny crystals, formed by Metamorphic rocks

growing slowly over time, on their surface.