4. The half-life of C-14 is 30 years. If a scientist had 100.0 g at the beginning, how
many grams would be left after 120 years has elapsed?
Half Lives
0
1
2
Time (years)
Amount (grams)
Show table

Answer:

Add a volume of a solution of known concentration is added to a volume of another solution in order to determine its concentration. Solutions in which a few drops of phenolphthalein have been added turn from colorless to brilliant pink as the solution turns from acidic to basic.

If you want the method:

Method

1) Use a pipette and pipette filler to add 25 cm3 of alkali solution to a clean conical flask.

2) Add a few drops of a suitable indicator and put the conical flask on a white tile.

3) Fill the burette with dilute acid. Flush the tap through to remove any air bubbles. Ensure the burette is vertical.

4) Slowly add the acid from the burette to the conical flask, swirling to mix. (The mixture may at first change colour, and then back again when swirled.)

5) Stop adding the acid when the end-point is reached (when the colour first permanently changes). Note the final volume reading.

6) Repeat steps 1 to 5 until three results are repeatable (in close agreement). Ideally these should lie within 0.10 cm3 of each other.

I hope it helps.

Answer:

To conduct a titration experiment, first fill the burette with an acid or base solution of known concentration. After that, take a burette reading from the top of the miniscus down to the bottom. Then, underneath the burette, place a flask containing an unknown concentration of acid or base. After that, fill the flask halfway with the appropriate indicator and shake it up. Add your titrate to the flask one drop at a time while stirring constantly. Continue to add the titrate until the color change is noticeable. Finally, take one more look at the burette to make sure everything is correct.

Explanation:

Hope it helps:)

Answer:

I could be wrong but i believe the answer is D. It was not B when i took the test

Explanation:

Answer:

2 MOLES OF GLUCOSE

Explanation:

How many Moles of glucose are produced from 12 moles of CO2 in photosynthesis?

6CO2 +6H20-------------->C6H12O6 -+ 6O20

(IN THE PRESENCE OF CHLOROPHYLL AND UV FROM )

)

6 MOLES OF CO2 MAKE 1 MOLE OF GLUCOSE

12 MOLES THEN MAKE 2 MOLES OF GLUCOSE

In the photosynthesis process, plants can use 12 moles of carbon dioxide to form 2 moles of glucose.

It is the process by which green plants and some other organisms convert light energy into chemical energy.

Let's consider the balanced equation for the synthesis of glucose through photosynthesis.

6 CO₂ + 6 H₂O ⇒ C₆H₁₂O₆ + 6 O₂

The molar ratio of CO₂ to C₆H₁₂O₆ is 6:1. The moles of glucose formed from 12 moles of carbon dioxide are:

12 mol CO₂  (1 mol C₆H₁₂O₆/6 mol CO₂) = 2 mol C₆H₁₂O₆

In the photosynthesis process, plants can use 12 moles of carbon dioxide to form 2 moles of glucose.

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According to conservation of matter, there should be equal amounts of all elements on both the reactant and product side.

Reactant:

1 Ca

1 C

1 O

Product:

1 Ca

1 C

3 O

Therefore, your friend is right because the law of conservation of matter is not followed in this chemical equation.

Answer:

option C 5

hope this answer helps you dear! take care

Answer:

5, the coefficient is the number right before the variable. The ² and ³ (even though Mines on top and yours is on the bottom) are not coefficient because. . . well it just doesn't make sense.

Answer:

True!

Explanation:

Avogadro’s law means that if we compare the number of helium molecules and the number of air molecules needed to inflate the same balloon, we would find the numbers the same.

The balloon filled with helium air, and the one blown by oneself with the same amount of air have the equivalent number of molecules. Thus, the given statement is true.

The moles are given as the mass of the compound with respect to the molar mass. According to the Avogadro's law, the 1 mole of a substance has the presence of the atoms equivalent to the Avogadro number.

In the balloons filled with oneself and individual there is same amount of gas, thus have same moles and thereby the number of molecules will be same in both the balloons. Thus, the given statement is true.

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Answer:

it may lead to read false measurements

while in an experiment.

that's what I think.

Answer:

It is most likely to be an asteroid

Answer:

C

Explanation:

Mixture of 2 or more metals is a compound

example is water which is made up of hydrogen and oxygen.

Answer:

1.68 atm (if temperature is constant)

Explanation:

p1 * v1 = p2 * v2

1 * 2.85 = p2 * 1.70

2.85 / 1.70 = p2

p2 = 1.6764

There are so many gas laws like Charles's law, Avogadro’s law and many more, out of which Boyle's law is one of the most important law among all gas laws. The pressure is required to compress the balloon to a volume of 1.70L is  1.6764 atm.

According to Boyle's law pressure is inversely proportional to volume at constant Temperature. It is applicable only on the ideal gases. Since temperature is constant here, we can apply this law.

Mathematically

P₁V₁=P₂V ₂

P₁= initial pressure of balloon =1.0atm

V₁= initial volume balloon =2.85L

P₂=final pressure balloon =?

V ₂=final volume balloon =1.70L

Putting all values

1 × 2.85 = P₂×1.70

2.85÷ 1.70 = P₂

P₂ = 1.6764 atm

Therefore, the pressure is required to compress the balloon to a volume of 1.70L is 1.6764 atm.

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Answer:

The answer is C) It is given off as heat

Explanation:

        Definition of unavailable energy : energy that cannot perform work while under the current conditions; see also available energy, energy deterioration, and entropy.

       Energy can transform from more useful forms into less useful forms, but it cannot be created or destroyed. It turns out that some energy gets transformed into an useless form in every real-world energy transfer or transformation.

    Entropy is the measurement of the amount of thermal energy per unit of temperature in a system that cannot be used for productive work. Entropy is a measure of a system's molecular disorder or unpredictability since work is produced by organized molecular motion.

   What is Mcq for McVisible Energy? Available energy is the largest portion of low-grade energy (heat) that is available for conversion. The smallest amount of heat that needs to be rejected is referred to as unavailable energy.

     For the system with two heat reservoirs undergoing this irreversible heat transfer, entropy increases. We'll see that this implies that the ability to use the transferred energy for work has been lost. Energy is no longer available to perform work due to the increase in entropy.

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Answer:

13.C

14.B

15.C

16.Chemical element

Chemical Element are called substance or element that cannot be decomposed or broken down into simpler substances by ordinary chemical process.

Chemical elements are those elements which cannot be chemically broken down into simpler substances and are primary constituents of all matter. They are fundamental ingredients of all matter in existence which can be combined in reaction to create chemical substance each chemical element in the universe has unique properties that distinguish it from all of the Other chemical elements. For example hydrogen is an element.

Hope that helps

Answer:

this is the answer

Explanation:

Neurons communicate with each other by sending chemical and electrical signals. Each neuron is connected with other neurons across tiny junctions called “synapses”. Impulses rush along tiny fibres, like electrical wires, from one neuron to the next. Electrical impulses travel through neurons.

Phenol can form hydrogen bonds with water since it contains O-H group but nitrobenzene can not form hydrogen bonds with water.

Polar molecules tend to be soluble in water. The greater the dipole moment, the greater the polarity of the compound. We can see that  Nitrobenzene has a dipole moment of 4.2 x 10-9 esu cm while phenol has a dipole moment of 1.7 x 10-8 esu cm.

Now, It is confusing to observe that the solubility of Nitrobenzene  in water is far less than that of phenol despite its higher dipole moment. The reason for this observation is that, phenol can form hydrogen bonds with water since it contains O-H group but nitrobenzene can not form hydrogen bonds with water.

Therefore, phenol is more soluble in pure water as a solvent compared to nitorbenzene.

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Answer:

C

Explanation:

because an ice is a solid and when it melts it becomes a liquid

Answer:

C

Explanation:

1) Which example shows a change in a state

of matter?

A. Liquid pouring

2

B. Wood Burning

1

C. Ice Melting

C  when ice melts it goes from a solid to a liquid state

Answer: adduction of the arm

lateral rotation of the arm

Explanation:

Answer:

Mercury fulminate is very sensitive to shock, friction, and sparks. ... put mercury fulminate into blasting caps for detonating dynamite.

Explanation:

Answer:

MgCO 3 is an inorganic salt with chemical name Magnesium Carbonate. It is also called Magnesite or Hydromagnesite or Barringtonite. Hydrated forms of magnesite such as di, tri, tetrahydrates are present as minerals. It acts as a fertilizer and as an antacid.

Answer:

B. C6H1206(s) + 602(9) → 6H20(l) + 6C02(9)

Explanation:

You can see that it's balanced;

C6H1206(s) + 602(g)           →            6H20(l) + 6C02(g)

 C  ⇒ 6                                                        C ⇒ 6

 H  ⇒ 12                                                       H ⇒ 6 x 2 = 12

 O  ⇒ 6 + (6 x 2) = 18                                  O ⇒ 6 + (6 x 2) = 18

Answer:

30.8 percent quartz, 4.5 percent feldspar, 3.6 percent carbonate, <0.5 percent iron oxides, 60.9 percent clay minerals, 1 percent organic material, and 2 percent other materials.

Answer:

Soil acidity can be corrected easily by liming the soil, or adding basic materials to neutralize the acid present. ... As lime dissolves in the soil, calcium (Ca) moves to the surface of soil particles, replacing the acidity. The acidity reacts with the carbonate (CO3) to form carbon dioxide (CO2) and water (H2O).

Explanation:

Answer:

for better understanding and visual understanding

Answer:

15ml

4HCl + 2Ba(OH)2 so moles ratio is 4:2

Answer:

i k ow its not the exact anwser but ih ope this helps

Explanation:

Energy plays a key role in chemical processes. According to the modern view of chemical reactions, bonds between atoms in the reactants must be broken, and the atoms or pieces of molecules are reassembled into products by forming new bonds. Energy is absorbed to break bonds, and energy is evolved as bonds are made. In some reactions the energy required to break bonds is larger than the energy evolved on making new bonds, and the net result is the absorption of energy. Such a reaction is said to be endothermic if the energy is in the form of heat. The opposite of endothermic is exothermic; in an exothermic reaction, energy as heat is evolved. The more general terms exoergic (energy evolved) and endoergic (energy required) are used when forms of energy other than heat are involved.

A great many common reactions are exothermic. The formation of compounds from the constituent elements is almost always exothermic. Formation of water from molecular hydrogen and oxygen and the formation of a metal oxide such as calcium oxide (CaO) from calcium metal and oxygen gas are examples. Among widely recognizable exothermic reactions is the combustion of fuels (such as the reaction of methane with oxygen mentioned previously).

Answer:

HBr

Explanation:

HBr (Hydrogen Bromide) is a polar molecule because of the unequal electronegativities of Hydrogen and Bromine atoms. Bromine has a higher electronegativity than hydrogen due to which electron bonded pair gets attracted slightly more towards bromine atom making HBr a polar molecule and resulting in a net dipole moment.

Answer:

A light bulb im guessing

Answer:

light bulb

Explanation:

when a light bulb is producing light it gets hot if you touch a light bulb while you will fill the heat

please choose my one as brainiest

The six parts of DNA serially are A) adenine B) thymine C) Sugars D) Phosphate E) Guanine F) Cytosine.

DNA  is a hereditary material  which is present in human beings as well as all other living organisms.  Every cell which is present in an organism's body has DNA  which is the same. Most of the DNA is situated in the cell's nucleus and small amount of it can be found in the cell's mitochondria as well.

Information which is stored in DNA is stored as codes made up of four chemical bases namely, adenine, thymine , cytosine and guanine.Human DNA consists of 3 billion bases .The order of the bases determines information which is required for building and maintaining an organism.

DNA bases are capable of pairing up with each other. Adenine pairs with thymine and guanine pairs up with cytosine .Each base is also attached to a sugar molecule  and a phosphate group. A base, phosphate sugar are together called as nucleotides.

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Answer:

78.125ml

Explanation:

Number of moles in 250ml of 2.5M KCl is (250÷1000)litres×2.5M so we divide these moles by 8M. The answer gotten will be in litres so multiply by 1000 to get it in ml