please help!! my grades dying
15 points

Answer:

what kind of school u doin? lol

Answer:

12)273.15 kelvin

13)223.15 kelvin

14)363.15 kelvin

15)253.15 kelvin

Explanation:

thank u!!!

Answer:

12) 273.15

13) 223.15

14) 363.15

15) 253.15

Explanation:

Formula:

_C+273.15=_K

Protons are important because they help keep the nucleus together, they also attract negatively charged electrons and keep them in orbit around the nucleus.

Answer:

It seems believable and familiar.

Explanation:

Plz mark Brainlest

Answer:

Concentration

Explanation:

Answer:

concintracion

Explanation:

Answer:the volume of the liquid increases

Explanation:

Answer:

The age of the earliest known human-like footprints is approximately 3000000 years.

Explanation:

Decay of isotopes is represented by the following ordinary differential equation:

[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)

Where:

[tex]\frac{dm}{dt}[/tex] - First derivative of mass with respect to time, measured in miligrams per year.

[tex]m[/tex] - Current mass of the isotope, measured in miligrams.

[tex]\tau[/tex] - Time constant, measured in years.

Now we proceed to obtain the solution of the differential equation:

[tex]\int\limits {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]

[tex]\ln m = -\frac{t}{\tau}+C[/tex]

[tex]m(t) = e^{-\frac{t}{\tau}+C }[/tex]

[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)

Where:

[tex]m_{o}[/tex] - Initial mass of the isotope, measured in miligrams.

[tex]t[/tex] - Time, measured in years.

[tex]\tau[/tex] - Time constant, measured in years.

We proceed to clear time within the formula presented above:

[tex]\ln \frac{m(t)}{m_{o}} = -\frac{t}{\tau}[/tex]

[tex]t = -\tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]

In addition, time constant can be found as a function of half-life:

[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)

If we know that [tex]t_{1/2} = 500000\,yr[/tex], [tex]m_{o} = 8\,mg[/tex] and [tex]m(t) = 0.125\,mg[/tex], the age of the earliest known human-like footprints is:

[tex]\tau = \frac{500000\,yr}{\ln 2}[/tex]

[tex]\tau \approx 721347.520\,yr[/tex]

[tex]t = -(721347.520\,yr)\cdot \ln \left(\frac{0.125\,mg}{8\,mg} \right)[/tex]

[tex]t \approx 3000000\,yr[/tex]

The age of the earliest known human-like footprints is approximately 3000000 years.

Fluorine atoms = 1.517 x 10²³

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

[tex]\large{\boxed{\boxed{\bold{mol=\frac{mass}{molar\:mass}}}}[/tex]

Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements

[tex]\tt mass~F=\dfrac{4.Ar~F}{MW~C_2F_4}\times mass~C_2F_4\\\\mass~F=\dfrac{4.19}{100}\times 6.3=4.788~gr[/tex]

[tex]\tt =\dfrac{4.788}{19}=0.252[/tex]

[tex]\tt 0.252\times 6.02\times 10^{23}=1.517\times 10^{23}[/tex]

Answer:

The equation for photosynthesis is 6 CO2 + 6 H2O + light --> C6H12O6 + 6 O2, so carbon dioxide will be found in the reactant part of the equation.

Answer:

The answer is 414.64 g the other answer is wrong

Explanation:

I took this assignment and got this question right

Answer:

you need to have a question or a problem first

The atomic mass of an atom is calculated by adding up protons and neutrons

There are two components that accompany an element, the mass number and atomic number

Atoms are composed of 3 types of basic particles (subatomic particles): protons, electrons, and neutrons

The charge of 1 proton is equal to a charge of 1 electron but has a different sign

The proton is positively charged (+1), the electron is negatively charged (-1). and neutrons not charged (neutral)

The Atomic Number (Z) indicates the number of protons and electrons in an atom of an element.

Atomic number = number of protons = number of electrons ⇒ neutral number

Atomic mass is the sum of protons and neutrons

Atomic Number (Z) = Atomic mass (A) - Number of Neutrons

Answer:

Its going to be D) In sigma bonds the electrons are in the space between the joined atoms and pi bonds above and below the joined atoms

Answer:

Science is the investigation of the ______________ ________________. Biology is the branch of science that studies living organisms and the environments they live in.

The scientific method is a tool used during a scientific investigation to answer a scientific question.

• Qualitative data is something that can’t be

collected but can change over time.

Scientific inquiry can’t answer questions about a person’s beliefs, ethics, values, and feelings.

im going to say d

Construct Hypotheses and Predictions

A hypothesis is a plausible guess for a particular fact. The hypothesis needs to be supported or refuted (proven wrong) based on collected evidence. All studies must have at least one hypothesis.

nevermind. I was wrong. I didn't see the other answers

Answer:

First One And Third Pls Mark Brainlest

Explanation:

The nucleus of an atom is held together by the strong nuclear force to hold together protons and neutrons. The strong nuclear force is stronger than electricity and gravity. It's even the strongest out of the four fundamental forces.

Answer:

Through a series of chemical reactions and tectonic activity, carbon takes between 100-200 million years to move between rocks, soil, ocean, and atmosphere in the slow carbon cycle. ... The acid dissolves rocks—a process called chemical weathering—and releases calcium, magnesium, potassium, or sodium ions.

Answer:

Fluorine belongs to the group 7 A so it must have 7 electrons in the oribits so the answer would be A as u count the electrons in the orbits, There are exactly 7 electron

Explanation:

Answer:

The DNA in prokaryotes is naked DNA.

Explanation:

Prokaryotes have cell walls which are a network of fibres that provides the cell with strength and rigidity. This network in the cell wall allows the cell to be freely permeable. These differ from eukaryotes which have a nucleus containing genetic information (DNA).

Answer: I think the ethanol in the solute and the sucrose is the solvent. Hope this helps!

Explanation: i learned this last year I think it is right?

A solvent is a chemical that dissolves a solute to produce a uniform solution. A solute is a substance that dissolves in a solvent, resulting in a homogeneous mixture. The solute is sucrose, and the solvent is ethanol.

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What are some of the regulations about cell phone waste?

In general, companies take part in the responsibility of taking back the e-waste resulted from their products.

Are the regulations the same everywhere, which countries have different regulations?

In 2005, two important directives were published in the European Union. The first stipulates that: 1) all manufacturers selling electrical and electronic equipment in and to EU countries label the equipment to inform customers that it must be recycled and 2) make sure that their products are properly disposed of or recycled after the life cycle. The second requires manufacturers to eliminate or minimize the use of lead, mercury, hexavalent chromium, cadmium, polychrome and diphelin biphenyl ethers in electrical and electronic equipment sold in the EU after 1 July 2006.

New technology to reduce waste?

Companies are trying to reduce the amount of resources needed in order to create their products. One alternative is the modular smarthphones, which aims to reduce the amount of e-waste of the phone by only upgrading a few elements of hardware.

Answer:

A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions. Generally, more reactive elements replace less reactive elements. A single replacement reaction occurs when one element replaces another element in one compound.

Explanation:

Just figured it out!

Answer: a double - replacement reaction

Explanation:

I just got it right on Apex

Answer:

The rate of a reaction is a measure of how quickly a reactant is used up, or a product is formed.

Explanation:

Answer: True

Explanation:

Solubility is a physical property. The reason is because it can be determined by simple observation and does not change the chemical composition of the material. If the material is soluble, the solubility is the maximum amount of material that dissolves in a solvent at a given temperature.

A physical property is a characteristic of matter that is not associated with a change in its chemical composition. Familiar examples of physical properties include density, color, hardness, melting and boiling points, and electrical conductivity.

Answer: True

Explanation: These are both examples of physical properties

Explanation:

A molecule with a negative pole and a positive pole is called a polar molecule.

(d) A molecule with two atoms of the same electronegativity

 A polar molecule is usually formed when the one end of the molecule is said to possess more positive charges and whereas the opposite end of the molecule has negative charges, creating an electrical pole.

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gravity is stronger on the earth, and gravity is what brings you back down

so, if there's less gravity, then there's more air time

Answer:

Low gravity

Explanation:

The moon has lower gravity than Earth, therefor when someone jumps, they will not return to the surface automatically.

Answer:

MnO4 − was reduced

C2 O4^2- was oxidized

Explanation:

2MnO4 −(aq)  +5H +(aq)  +2 C2 O4^2-(aq)  +6H+(aq)  →2Mn2+(aq) + 10CO2(g)  +8H2 O(l)

A redox reaction is characterized by a change in the oxidation number of reacting species from left to right in the reaction equation.

If we look at Manganese, its oxidation number was decreased from +7 on the left hand side to +2 on the right hand side. This implies that it gained five electrons. recall that reduction refers to electron gain.

If we look at carbon, its oxidation number increased from +3 on the left hand side to +4 on the right hand side. This indicates loss of one electron and oxidation refers to electron loss.

MnO₄⁻ was reduced and C₂O₄²⁻ was oxidized in the titration.

The balanced chemical equation for the reaction can be expressed as:

[tex]\mathbf{6H^+_{(aq0} + 2MnO_4^-_{(aq)} + 5H_2C_2O_4 _{(aq)} \to 10CO_{2(g)} +8H_2O_{(l)} + 2Mn^{2+}_{(aq)}}[/tex]

A redox reaction can be described by a variation in the oxidation number of reacting species in the chemical reaction equation from the reactant side to the product side

Let consider Mn in MnO₄⁻, its oxidation number was decreased from +7 on the reactant side to +2 on the product side. This shows a gain of additional five electrons.

Thus, MnO₄⁻ is reduced.

Also in C₂O₄²⁻, the oxidation number of carbon increases from +3 on the reactant side to +4 on the product side. Since an electron is lost, then oxidation  occurs at C₂O₄²⁻  

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