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Answer:

1.chemical change 2, when two chemicals are mixed they have mix two chemcials into one liquid

Explanation:

Answer:

yes, in certain cases

there are different types of bondings between atoms

and in some they lend electrons to make their atom stable this type of bonding is called ionic bonding

and in covalent bond the atoms share their electrons

Answer:

0.123 mol

Explanation:

1 mol Na/22.99g na=0.123 mol

Answer:

[tex]\boxed {\boxed {\sf 0.261 \ mol \ B}}[/tex]

Explanation:

We are asked to find the number of moles in a sample of 2.82 grams of boron.

We convert grams to moles using the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table. They are equivalent to the atomic masses, but the units are grams per mole instead of atomic mass units.

Look up the molar mass of boron (B).

Convert using dimensional analysis. Set up a conversion factor using the molar mass.

[tex]\frac {10.81 \ g \ B}{ 1 \ mol \ B}[/tex]

We are converting 2.82 grams of boron to moles, so we multiply by this value.

[tex]2.82 \ g \ B *\frac {10.81 \ g \ B}{ 1 \ mol \ B}[/tex]

Flip the ratio so the units of grams of boron cancel.

[tex]2.82 \ g \ B *\frac { 1 \ mol \ B}{10.81 \ g \ B}[/tex]

[tex]2.82*\frac { 1 \ mol \ B}{10.81}[/tex]

[tex]\frac {2.82}{10.81} \ mol \ B[/tex]

[tex]0.2608695652 \ mol \ B[/tex]

The original value of grams has 3 significant figures, so our answer must have the same. For the number we found, this is the thousandth place. The 8 in the ten-thousandth place tells us to round the 0 up to a 1.

[tex]0.261 \ mol \ B[/tex]

There are approximately 0.261 moles of boron (B)in 2.82 grams of boron.

The concentration of 25 mL of potassium hydroxide can be determined from 0.1 M solution of hydrobromic acid by titration.

Titration involves the process by which the concentration of an unknown solution is determined by reaction a known volume of the unknown solution with a carefully measured volume of a standard solution. By determining the volume of the standard solution required to react completely with the solution of unknown concentration, its concentration can be accurately determined by calculation.

In order to determine the concentration of  25 mL of potassium hydroxide, this volume of solution is put into a conical flask and titrated against a known volume of 0.1 M solution of hydrobromic acid. At the end point, usually signified by a color change, the concentration of the 25 mL of potassium hydroxide solution can be calculated from the stoichiometry of the reaction.

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Answer:

Light waves come in a continuous variety of sizes, frequencies and energies, a continuum known as the electromagnetic spectrum. Once Maxwell introduced the concept of electromagnetic waves, everything clicked into place.

Explanation:

Hope this helps:)

~Kisame'sAbs

Answer:

When the energy is passed on from one trophic level to another, only 10 percent of the energy is passed on to the next trophic level.

Explanation:

Answer:

The controlled variable of an experiment is the one thing that stays the same in an experiment.

Explanation:

An example would be : if I have two pennies, both dunked in water, but than I change one to be dunked in vinegar, the one dunked in water still is the constant or the controlled variable.

Answer:

A pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample. Mixtures are physical combinations of two or more elements and/or compounds.

Answer:

The Lewis structure for XeF4 has a total of 36 valence electrons. When we are done adding valence electrons we check each atom to see if it has an octet (full outer shell). We also need to check to make sure we only used the number of available valence electrons we calculated earlier (no more, no less).

Explanation:

Answer:

Even though i cannot see the image, In chemistry, a mixture is a material made up of two or more different chemical substance/substances which are not chemically combined. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.

Explanation:

Answer:

in f1 its shows all hybrid red

Explanation:

RR rr

R R

Explanation:

Answer:

A type of an atom which has a different number of neutrons but the same atomic number, therefore making it the same element. This atom would still have the same properties as well. (Ex: Vanadium-51 is an isotope of Vanadium that has 51 neutrons but still has 23 protons, as its atomic number is 23.)

Isotopes are variants of an element that have the same number of protons in their atomic nucleus, identifying them as the same chemical element, but differ in the number of neutrons.

The variations in neutron numbers among isotopes lead to differences in their atomic masses, resulting in isotopes having slightly different physical properties while retaining similar chemical behavior.

For example, in the case of boron, the two isotopes listed may have the same number of protons (5), but one has 6 neutrons, and the other has 7 neutrons, leading to slightly different atomic masses.

Similarly, for carbon and oxygen, the isotopes exhibit variations in neutron numbers while maintaining the same number of protons, defining them as isotopes of the respective elements. Isotopes play a crucial role in various scientific fields, including radiometric dating, nuclear energy, and medical imaging.

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Answer:

Questions are an essential part of science. ... They state the final question in a way that can be answered by investigation or experiment. A good scientific question is: “What effect does the pH of water have on radish seed germination?” Good scientific questions are defined, measurable, and controllable.

Answer:

vc

Explanation:

cvcv

toward, more

away from, less

Explanation:

When the northern hemisphere is tilted toward the sun, the sunlight is more direct than it is in the southern hemisphere. This explains why it's wintertime in Australia while at the same time, it's summertime in the US.

When the northern hemisphere is tilted away from the sun, the sunlight is less direct than it is in the southern hemisphere. This explains why it's summertime in Australia while it's wintertime in the US.

Answer:

HClO4 + KOH → KClO4 + H2O

Explanation:

Answer:

HCIO4 + KOH → KCIO4 + H2O

Explanation:

nailed it

Answer:

7.50 and 50L

35atm

6.2atm

Answer:

b

Explanation:

i just had the same question

Answer:The answer is 8-14

Explanation:It can range from 9-10 or

or above to 14 depending on the amount of leached wood ash(lye) a.k.a potassium carbonate which is an alkalline compound

Answer:

8-14

Explanation:

Answer:

Butanoic acid and 2-propanol reacts to form isopropyl butyrate.

Explanation:

brainliest plz

Answer:

ssihh add then htit da

Explanation:

The frequency of this line of vanadium  is 9.38 x10 ^14 Hz.

Emission spectrum shows how the electron of an atom goes or moves  from a higher to a lower energy level.

Now The energy of a photon is given by

E = hc/λ

where  

h = Plank's constant =  6.626 x 10⁻³⁴ J s

c = speed of light=   3 x 10⁸ m/s

λ = wavelength =  318.5  x 10⁻⁹ m  

Solving

E =  (6.626 x 10⁻³⁴ J s x 3 x 10⁸ m/s)  / 318.5  x 10⁻⁹ m

E =6.2166 x10 ^-19 J

Also, we know that energy is related to frequency by the equation

E =hf

Where;

h = Planks's constant

f = frequency of photon

Making frequency subject of the formulae

f = E/h

f =6.2166 x10 ^-19 J/  6.626 x 10⁻³⁴ J s

f =  9.38 x10 ^14 Hz

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Answer:

water and vinegar

:salad

Explanation:

There is two kind of mixture the heterogeneous and homogeneous mixture.Which water and vinegar is the homogeneous and the salad is heterogeneous mixture based on my example above.

Answer:

1) 37100000

2) 330000000

Explanation:

1) 3.7 x 10^7 = 37100000

2) 3.30 x 10^8 = 330000000

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Answer:

the liquid becomes equal to the rate of condensation

Explanation:

ive come across this question before! and i think its right! :D

The vapor pressure of a liquid at a provided temperature is measured when the rate of evaporation of a liquid evolves equally to the rate of condensation.

Evaporation is the procedure by which water transforms from a liquid to a gas or vapor.

Evaporation is the primary route that water moves from the liquid circumstances around into the water cycle as atmospheric water vapor.

When a molecule around the surface absorbs adequate energy to overwhelm the vapor pressure, it will exit and join the surrounding air as a gas.

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Answer:

B

Explanation:

equilibrium happens when two things are in complete balance and thermal is in reference to heat so two things are in thermal equilibrium once they have the same temperature.

The option which indicates that two objects are in thermal equilibrium is the objects that have the same temperature. Thus, the correct option for this question is B.

Thermal equilibrium may be defined as a state of a system in which all the parts of the system occupy the same temperature. Two or more objects are in thermal equilibrium if there is no net flow of thermal energy or heat between them when they are considerably connected by a path permeable to heat.

The mechanism of thermal equilibrium occurs when a cup of hot coffee is put on the table and after a short period of time, the temperature of the coffee is the same as the surrounding temperature. So, this represents an example of thermal equilibrium.

Therefore, the correct option for this question is B.

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Answer:

Drawing conclusions

Explanation: