How have organisms changed over time, according to the fossil record?​

Answer:

Solution given:

specific heat capacity of water [c]4.186 J/g °C

temperature[∆T]=?

mass[m]=3g

heat[Q]=8000J

we have

Q=mc∆T

8000=3*4.186*∆T

∆T=8000/12.558

∆T=637.04°C

the temperature change is 637.04°C.

Answer:

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Explanation:

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Answer:

need help asap electrons

positively charged, subatomic particles found in the nucleus of the atom

2. metals

elements with properties intermediate between those of metals and nonmetals

3. period

a homogeneous mixture whose particles are too small to reflect or scatter light

4. compound

two or more elements that have chemically combined

5. solution

elements that are malleable, polish to a luster, conduct heat and electricity well and tend to lose electrons in a chemical reaction

6. protons

a vertical column on the periodic table

7. group

a horizontal row on the periodic table

8. metalloids

negatively charged, subatomic particles

Explanation:

We are given:

Volume = 2 L

pH = 2.75

Finding the concentration required:

we know that pH is just the negative log of the hydrogen ion concentration

pH = -log[H⁺]

we are given that the pH is 2.75

2.75 = -log[H⁺]

log[H⁺] = -2.75                         [multiplying both sides by -1]

[tex]10^{log[H]} = 10^{-2.75}[/tex]                      

[H⁺] = 1.78 * 10⁻³ Molar

Number of moles of Hydrogen ions:

[H⁺] = 1.78 * 10⁻³ Molar

which means that there are 1.78 * 10⁻³ moles of hydrogen ions in 1 liter solution

1.78 * 10⁻³ moles / L

multiplying and dividing by 2, we get:

3.56 * 10⁻³ moles / 2 L

Hence we need 3.56 * 10⁻³ moles of hydrogen ions  

Answer:

3.556x 10^-3mol

Explanation:

Using pH =-log [ H+], we can calculate the concentration of the hydrogen Ions.

pH =-log [ H+], pH = 2.75

2.75 = -log[H+], taking antilog of both sides

10^ — 2.75 = [H+]

[H+] =1. 778 x 10^-3M

Now that we have the concentration and also knows the volume, we can use the relation

Moles = concentration X volume

= 1. 778 x 10^-3M x 2L = 3.56x 10^-3mol

The moles of the hydrogen Ions is 3.56x 10^-3mol

Answer: 23 g

Explanation:

Amountafter = Amountbefore * (1/2)^(t/thalf)

Amountafter = (750 grams) * (1/2)^(62.0 hours/12.4 hours)

Amountafter = 23.4375 grams

750 has 2 significant digits

12.4 and 62.0 have 3 significant digits

So we take the lower of 2 significant digits:

23 grams

The half-life of 42K is 12.4 hours. 23.4375 grams of a 750 grams sample left after 62.0 hours.

Half life is the amount of time required to reduce to one-half of its initial value. The symbol of half life is [tex]t_{1/2}[/tex].

It is expressed as:

[tex]N(t) = N_{0} (\frac{1}{2})^{\frac{t}{t_{1/2}}[/tex]

where,

N(t) = quantity remaining

N₀ = initial quantity

t = elapsed time

[tex]t_{1/2}[/tex] = half-life of the substance

Here,

N₀ = 750.0 g

t = 62 hr

[tex]t_{1/2}[/tex] = 12.4

Now put the values in above equation we get

[tex]N(t) = N_{0} (\frac{1}{2})^{\frac{t}{t_{1/2}}[/tex]

[tex]N(t) = 750 \times (\frac{1}{2} )^{\frac{62}{12.4}}[/tex]

[tex]N(t) = 750 \times (\frac{1}{2})^5[/tex]

[tex]N(t) = 750 \times \frac{1}{32}[/tex]

N(t) = 23.4375 grams

Thus, from the above conclusion we can say that the 23.4375 grams of a 750 grams sample left after 62.0 hours.

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The balanced equation of the reaction is:

[tex]O_2 + 2 NO[/tex] ⇒ [tex]2 NO_2[/tex]

Every gas occupied 24 L in one mole in r.t.p. according to the equation:

[tex]24 \times n = V[/tex]

8/24=0.333 mol

2 moles of NO makes 2 moles of [tex]NO_2\\[/tex] so

0.333*24=8L

Answer:

Energy

Explanation:

Answer:

D)subscript of C in molecular formula = n x subscript of C in empirical formula

Explanation:

THIS IS THE COMPLETE QUESTION BELOW;

.The empirical formula for a compound is CH2. If n is a whole number, which shows a correct relationship between the molecular formula and the empirical formula? a)<br /><br /> empirical formula mass / molecular mass = n<br /><br /> B) molecular mass = element mass / empirical formula mass ´ 100<br /><br /> c) subscript of H in empirical formula = 2  subscript of H in molecular formula<br /><br /> D) subscript of C in molecular formula = n  subscript of C in empirical formula<br /><br />

An empirical formula can be regarded as "shorten form" of a molecular formula. Instance of this is

A compounds CH4, C2H8, C4H12... with empirical formula of CH4. In this case a constant "n" represent the difference that exist between empirical formula and molecular formula, "n" which is a whole number, molecular formula is the numerator.

Therefore, subscript of C in molecular formula = n x subscript of C in empirical formula

Gamma decay, type of radioactivity in which some unstable atomic nuclei dissipate excess energy by a spontaneous electromagnetic process. In the most common form of gamma decay, known as gamma emission, gamma rays (photons, or packets of electromagnetic energy, of extremely short wavelength) are radiated.

Answer:

Compounds contain more than one type of material. Yet both compounds and elements are considered pure substances. 

Pure compounds are created when elements combine permanently, forming one substance

Extra:

So, a mixture can be separated into its original components, while a pure compound cannot.

Answer:

[tex]\boxed {\boxed {\sf 60 \ mL}}[/tex]

Explanation:

In this problem, volume and pressure are changing, so we use Boyle's Law. This states that the volume of a gas is inversely proportional to the pressure. The formula for this law is:

[tex]P_1V_1=P_2V_2[/tex]

Originally the gas has a volume of 30 milliliters and a pressure of 4 atmospheres.

[tex]4 \ atm * 30 \ mL=P_2V_2[/tex]

The pressure is changed to 2 atmospheres, but the new volume is unknown.

[tex]4 \ atm * 30 \ mL = 2 \ atm *V_2[/tex]

We want to solve for the new volume (V₂). It is being multiplied by 2 atmopsheres. The inverse operation of multiplication is division, so we divide both sides by 2 atm.

[tex]\frac{4 \ atm * 30 \ mL}{ 2 \ atm}= \frac{ 2 \ atm *V_2}{2 \ atm}[/tex]

[tex]\frac{4 \ atm * 30 \ mL}{ 2 \ atm}= V_2[/tex]

The units of atmospheres (atm) cancel.

[tex]\frac{4 * 30 \ mL}{ 2 }= V_2[/tex]

[tex]\frac{120 \ mL}{2}= V_2[/tex]

[tex]60 \ mL= V_2[/tex]

The new volume of the gas is 60 milliliters.

Answer:

Lithium chloride + Iron

No reaction takes place, because lithium is more reactive than iron, so Iron cannot displace lithium from its solution.

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Answer:

they become water vapor and after that, they become a type of precipitation

Answer:

It is unsaturated

Explanation:

A solution is said to be unsaturated when it contains less solute than it can normally hold at a given temperature.

The solubility of NaCl remains fairly independent of temperature hence the line for the solubility of NaCl remains fairly flat in the solubility curve.

The solubility of NaCl is about 36 g of NaCl in 100g of water. Hence a solution that contains 35.00 g of sodium chloride in 100 g of water at 45.0C is unsaturated.

ano ang naakit sa isang tao..at kung ano ang iyong kasarian ay

Answer:

that heat energy speeds up the motion of the particles and the temperature of the reaction

Explanation:

HOPE IT HELPS

When we place an ice pack on a sprained ankle, the blood flow is reduced which prevents  further swelling, ice reduces the blood flow which is necessary  when  the ankle is injured.

The flow of blood and the lymph vessel is limited or decreased after applying an ice pack, this is an immediate  first aid to be given to the injured person

After 2-3 days of the injury, a hot  pack should  be applied to increase the blood flow and the lymph flow for an activity.

Hence, the molecule flow is reduced after applying an ice pack to the sprained ankle

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Answer: 0.048 kPa

Explanation: no clue i just looked it up you’re welcome y’all:)

Answer:

See explanation

Explanation:

A balanced chemical reaction equation has the same number of atoms of each element on both sides of the reaction equation.

Hence, for the reaction between KOH and H2SO4, the balanced chemical reaction equation is;

H2SO4(aq) + 2KOH(aq) ---------> K2SO4(aq) + 2H2O(l)

Complete ionic equation;

2H^+(aq) + SO4^2-(aq) + 2K^+(aq) +2OH^-(aq) -------> SO4^2-(aq) + 2K^+(aq) + 2H2O(l)

Net ionic equation;

2H^+(aq) + 2OH^-(aq) -------> 2H2O(l)

Answer:

20.0% w/v A

Explanation:

A 20.0 w/V...

Answer:

B) Theoretical

Explanation:

Just did the question

Answer:

20 cajas - 600 gramos

Explanation:

Veamos los datos informados:

1 caja → 5 porciones

1 caja → 30 g

Si queremos preparar 100 porciones, indudablemente necesitamos:

100 porciones . 1 caja / 5porciones = 20 cajas

Finalmente ya sabemos que una caja tiene 30 g

Entonces, si tenemos 20 cajas . 30 g / 1 caja = 600 g

En conclusión:

Necesitamos una masa total de 600 gramos  en 20 cajas

Answer:

The answer is C. 40.0 mL.

Explanation:

To solve for the volume of KOH, start by using the formula [tex]N_{B}[/tex][tex]V_{B}[/tex] = [tex]N_{A}[/tex][tex]V_{A}[/tex] and label the information given in the question. The B in the formula stands for the base solution, and the A in the formula stands for the acid solution.

[tex]N_{B}[/tex] = 0.050 M KOH

[tex]V_{B}[/tex] =   ?    

[tex]N_{A}[/tex] = 0.0100 M HNO3

[tex]V_{A}[/tex] = 200. mL  

Next, use the formula [tex]N_{B} V_{B} = N_{A}V_{A}[/tex], and in order to find the volume for the base solution, the formula will have to be derived for [tex]V_{B}[/tex]. The formula will now look like [tex]V_{B}= \frac{N_{A} V_{A} }{N_{B} }[/tex].

Then, plug in the information given in the question. The equation will look like [tex]V_{B}= \frac{(0.0100 M HNO_{3} {})(200. mL) }{0.050 M KOH}[/tex]. Finally, solve the equation, and the answer will be 40.0 mL.  

Answer:

The correct answer is - 62.36 g.

Explanation:

Given:

Mass of substance - 200

decreasing rate - 11% per day

mass at the beginning of the 10th day - ?

Solution:

F(x) = 200*(1 - 11)^x

here x the time

F(x) = 200* (0.89)^10

= 200*0.3118

= 62.3634

Thus, the correct answer is 62.36 g.

Answer:

True

Explanation:

Trust me

Answer:

True. Kinetic energy is the energy of motion. All moving objects have kinetic energy. When an object is in motion, it changes its position by moving in a direction: up, down, forward, or backward.

Answer:

Each orbit has a specific energy level.

Would you mind marking it the brainliest:).

Answer:

Beginning from the innermost layer and moving towards the outermost of the sun that has six layers.

1. Innermost layer is the core: All the energy of the sun comes from core. Here hydrogen and helium are components that are present.

2. Radiative zone: The high-energy photons are move from the innermost core to the second innermost radiative zone.

3. Convective zone: It is a comparatively cooler layer to the core and radiative zone.

4. Photosphere: It is the 4th innermost region with sunspots and called the magnetic field of the sun.

5. Chromosphere: This red color layer with filaments of gas is cooler than the photosphere.

6. Corona: It is the outermost layer of the sun and the temperature is much higher here.

H2SO4 + 2KCL ----------› K2SO4 + 2HCL

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