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Answer:

This is true

Explanation:

Answer:

1.mole allows us to weigh convenient amounts of material containing known numbers of atoms; i.e., it allows us to count atoms

2. H202 :34.0147 g/mol

C2H6: 30.07 g/mol

Answer:

PET works by using a scanning device (a machine with a large hole at its center) to detect photons (subatomic particles) emitted by a radionuclide in the organ or tissue being examined.

Newer technology combines PET and CT into one scanner, known as PET/CT. PET/CT shows particular promise in the diagnosis and treatment of lung cancer, evaluating epilepsy, Alzheimer's disease and coronary artery disease.

Explanation: Most Brainliest Please

Answer:

a 17 bc it is how it works

Girls are usually completely physically mature by 18 years old.

Puberty refers to the physical transformation of a child's body into an adult one capable of fertile reproduction.

In girls puberty generally attains before two years earlier than the boys. And the exact age of the girls to attain puberty is in between the age of 10 to 14.

Hence the age of girls to attain puberty is 14.

To know more about puberty, visit the below link:

https://brainly.com/question/25821562

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Answer:

Physical change occur when objects or sub undergo a change that does not change their chemical composition.

Chemical change us a permanent change which occur when a substance combined with another to form a new substances.

Answer:

D: When the acidity of a solution increases, the pH increases.

Explanation:

It is totally wrong to assert that when the acidity of a solution increases, the pH of the solution will increase

The right answer is that when the acidity of a solution increases, the pH value decreases.

Answer:Boiling point of a solution is found to be 100.34  

o

C. Boiling point of pure

water is 100  

o

C.      

The elevation in the boiling point ΔT  

b

​  

=100.34−100=0.34  

o

C.

12 gm glucose (molecular weight 180 g/mol) is dissolved in 100 gm water.

The number of moles of  glucose =  

180g/mol

12g

​  

=0.0667mol

Mass of water =100g×  

1000g

1kg

​  

=0.100kg

Molality of solution m=  

0.100kg

0.0667mol

​  

=0.667mol/kg

The elevation in the boiling point ΔT  

b

​  

=K  

b

​  

×m

0.34  

o

C=K  

b

​  

×0.667mol/kg

K  

b

​  

=0.51  

o

Ckg/mol

The molal elevation constant for water is 0.51  

o

Ckg/mol.

Explanation:

Answer:

v = 16.49 m/s

Explanation:

Given that,

Length of the string, l = 1.15 m

The ball makes 137 complete turns each minute.

We know that, 1 turn = 6.28 rad

137 turns = 860.79 rad

1 min = 60 s

[tex]\omega=\dfrac{860.79\ rad}{60\ s}\\\\=14.34\ rad/s[/tex]

We need to find the tangential velocity of the ball. It can be given by

[tex]v=r\omega\\\\=1.15\times 14.34\\\\v=16.49\ m/s[/tex]

So, the tangential velocity of the ball is 16.49 m/s.

Answer:

B. The coefficients give the molar ration of the reactants

Explanation:

Answer:

The correct option is A

Explanation:

Radium is an atom with the atomic number of 88. It is a metal found in group 2 of the periodic table; meaning that it has two valence electrons in it's outermost shell. As a metal that wants to form an ionic compound, radium would have to lose these two valence electrons to become a divalent positively charged cation (Ra²⁺). Thus, the correct option is A

Answer:

Gamma ray

Hope this helps!!!!!!!!

Credit: https://climate.nasa.gov/causes/

The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to about 417 parts per million in the last 151 years. The panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in Earth's temperatures over the past 50-plus years.

The panel's full Summary for Policymakers report is online at https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_summary-for-policymakers.pdf.

Answer:

When sleeping the energy exhibited is Potential energy. When I wake up and I’m preparing for the day I use kinetic energy which is the energy exhibited during motion.

Eating before leaving the house means I used chemical energy for replenishment of nutrients to aid the performance of more activities for the day. The food eaten and the physical activities also give rise to thermal energy which is why we sweat.

Answer:

It's called "Great conjunction"

Answer:

solid ,hard, not see through

Explanation:

Answer:

There are many properties out there, so three include bright yellow color, luster shine, and the maleability that determines the durability.

Answer:C

Explanation:oxygen,light,and glucose combine to produce high energy molecules

Answer:

c

Explanation:

I got this answer right so trust me

Answer:

The percentage by mass of lithium in one mole of Li₃N is approximately 59.78%

Explanation:

The given compound is Li₃N

The atomic mass of lithium, Li = 6.94 amu

The atomic mass of nitrogen, N = 14.01 amu

Therefore by definition, we have;

The mass of one mole of lithium, Li = 6.94 g

The mass of one mole of nitrogen, N = 14.01 g

One molecule of Li₃N contains 3 atoms of lithium, Li and 1 atom of nitrogen, N

The mass of one mole of Li₃N = The molar mass of Li₃N = 3 × The mass of one mole of lithium + The mass of one mole of nitrogen

∴ The mass of one mole of Li₃N = 3 × 6.94 g + 14.01 g = 34.83 g

The percentage by mass of lithium, Li, in one mole of Li₃N = 3×6.94/(34.83) × 100 ≈ 59.78%

The percentage by mass of lithium in one mole of Li₃N ≈ 59.78%.

Answer:lossed

Explanation:

Answer:

2.54mole of H₂

Explanation:

The reaction expression is given as:

           2H₂O  →   2H₂  +   O₂

Given;

Number of moles of H₂O  = 2.54moles

Unknown:

Number of moles of H₂ produced  = ?

Solution:

To solve this problem, we use the concept of mole comparison. Now from the reaction expression, we know that;

                  2 mole of H₂O will produce 2 mole of H₂

                 2.54 mole of H₂O will then produce 2.54mole of H₂

Answer: The spectrum would be continuous

Explanation:

Atomic transitions allow us to find that the correct answer to what would happen if there was no quantization is:

          d. the spectrum would be continous

In the models of atoms the correct explanation for the energy was given by Planck, by establishing that the energy of an electron is:  

           E = h ν

Where E is the energy, h the Planck constant and ν the frequency.

Therefore a transition occurs as the jump of an electron from one level to another  

          ΔE = E₂ - E₁

In all atomic models the levels are discrete, so the jumps are also discrete.

If the levels were continuous, the energy difference between the lines disappears and we have a continuous emission spectrum.

Let's review the different answers:

a. False. The lines disappear

b. False. This for if the separation between levels increases, which is the opposite process to the one analyzed.

c. False. The lines disappear

d) True. The spectrum is a continuum without any separation.

In conclusion, using the atomic transitions we find that the correct answer for what would happen if there was no quantization is:

     d. the spectrum would be constnuous

Learn more here: brainly.com/question/19426165

Answer:

4.207

Explanation:

PH = -log .000062=4.207

Answer:

Condensation 212F or 100C, Freezing 32F or 0C

Explanation:

Condensation 212 degrees Fahrenheit or 100 degrees Celsius.

Freezing point 32 degrees Fahrenheit or 0 degrees Celsius.

Rate of  consumption of  N₂ = - 1.25 x 10⁻⁴

The reaction rate (v) shows the change in the concentration per unit time.  

[tex]\tt rate=\dfrac{concentration(M)}{time(s)}[/tex]

The rate reaction for Haber Bosch :

N₂(g)+3H₂(g)⇒2NH₃(g)

From equation, mol ratio N₂ : NH₃ = 1 : 2, so

the rate of formation of ammonia = 2 x the rate of consumption of nitrogen.

Given

the rate of formation of ammonia gas : 2.5x10⁻⁴ M/s

the rate of consumption of nitrogen :

[tex]\tt \dfrac{2.5\times 10^{-4}}{2}=1.25\times 10^{-4}[/tex]

The sign negative for consumption : -1.25 x 10⁻⁴ M/s

or we can use another way:

Rate of formation of  NH₃  = reaction rate x coefficient of  NH₃

2.5 x 10⁻⁴ = reaction rate x 2

reaction rate = 1.25 x 10⁻⁴

Rate of  consumption of  N₂  = reaction rate x coefficient of N₂

Rate of  consumption of  N₂ =  1.25 x 10⁻⁴ x 1

Rate of  consumption of  N₂ =  1.25 x 10⁻⁴