What is the answer, just the letter. No explanation needed

What Is The Answer, Just The Letter. No Explanation Needed

Answers

Answer 1

Answer:

Explanation:

f i did this in my class

Answer 2

Answer:

3 rd

Explanation:

yes answer is 3 you can go with it


Related Questions

Bubbles are released when nitric acid is added to a potassium carbonate solution.
What is the net ion

Answers


Hi can I have a shout out please thank you for your reply thank you for the wonderful reply thank me love

9.
Which element is most likely to conduct heat and electricity?
A. Na B. Ca C.P D. Ne

Answers

Answer:

A. Na

Explanation:

Sodium is a good conductor of electricity and heat because it has only one electron in its valence shell.

i hope this helps :)

Answer:

C.) P

Explanation:

I believe this is correct, lmk if it's not.

how many miles will a person run an 800 km race?

Answers

Answer:

uhh its 497 miles

Explanation:

Question 13 (3 points)
.Which one of the following is not a scientific variable?
independent
statement
O control
dependent

Answers

The answer is the D. "Observation" is not a variable in an experiment.
Explanation: Research variables are factors that can be manipulated, measured or those that we try to explain through other variables. "Observation" is not a variable in an experiment, but it is the first step and fundamental part in the scientific method, in which the experiments are contained (experimentation stage). Observation is the information recorded during an experiment, obtained through the senses or through the registration of information on scientific instruments.

An effective treatment for some cancerous tumors involves irradiation with "fast" neutrons. The neutrons from one treatment source have an average velocity of 3.5×107 m/s. If the velocities of individual neutrons are known to within 2.0% of this value, what is the uncertainty in the position of one of them?

Answers

Answer:

4.54 * 10^-14 m

Explanation:

From Heisenberg's uncertainty principle, we can write;

Δp.Δx ≥ h/4π

Given that;

Δp =Δmv

So;

Δmv.Δx ≥h/4π

Δmv =2/100(3.5×10^7 m/s * 1.66 * 10^-27)

Δmv =1.162 * 10^-21 Kgms-1

Δx ≥6.63 * 10^-34 /4 * 3.142 * 1.162 * 10^-21

Δx ≥4.54 * 10^-14 m

What is the molecular mass for a non-electrolyte if 35.0 g of it is dissolved in 45.0 grams of water and the solutions boiling point is 101.25oC? (The KB for H2O is .51°C/m)

Answers

The boiling point of water increases as the amount of impurities dissolved in it increases. For our purposes, we will consider the non-electrolyte to be the dissolved impurity. The change in the boiling point can be calculated using the equation:

[tex]\Delta T_b = i \times K_b \times m[/tex]

where [tex]\Delta T_b[/tex] is the change in boiling point, [tex]i[/tex] is the van ‘t Hoff factor (whose value denotes the number of particles each formula unit of the dissolved substance dissociates into in water), [tex]K_b[/tex] is the boiling point elevation constant, and [tex]m[/tex] is the molality (moles of solute/kilogram of solvent) of the solution.

Right off the bat, since we're dealing with a non-electrolyte, the dissolved substance can be assumed not to dissociate in water. So, our van ‘t Hoff factor, [tex]i[/tex], would be 1 (by contrast, the [tex]i[/tex] for an ionic compound like NaCl would be 2 since, in water, NaCl would dissociate into two particles: one Na⁺ ion and one Cl⁻ ion). We're also given our [tex]K_b[/tex], which is 0.51 °C/m.

Assuming the normal boiling point of pure water to be 100 °C (a defined value for sig fig purposes), the change in boiling point from having dissolved 35.0 g of the non-electrolyte can be obtained by subtracting 100 °C from the final—elevated—boiling point of 101.25 °C:

[tex]\Delta T_b = 101.25\text{ }^o\text{C} - 100\text{ }^o\text{C} = 1.25\text{ }^o\text{C}[/tex]

Now, recall what we're asked to determine: the molecular mass of the dissolved substance. There is one unknown left in the equation: the molality of the solution. Let's first solve for that:

[tex]m = \frac{\Delta T_b}{K_b} = \frac{1.25^\text{ o}\text{C}}{0.51^\text{ o}\text{C}/m} \\ m = 2.45 \text{ mol solute/kg water}.[/tex]

Notice that we didn't include the i since its value is 1.

Now, what would happen if we multiplied our molality by the mass of water we've been given? We would be left with the moles of solute. And what are we asked to find? The molecular mass, or the mass per mole. We can accomplish this in two steps. Remember to convert your mass of water to kilograms:

[tex]2.45 \text{ mol solute/kg water} \times 0.045 \text{ kg water} = 0.110 \text{ mol solute.}[/tex]

And, finally, we divide the mass of our solute by the number of moles of solute:

[tex]\frac{35.0 \text{ g solute}}{0.110 \text{ mol solute}} = 317.5 \text{ g/mol}[/tex]

Our answer to two significant figures (which is the number of sig figs to which our [tex]K_b[/tex] is given) would be 320 g/mol.

AgNO3 ionic or covalent

Answers

Answer:

what i need more details

Explanation:

Answer:

Ionic

Explanation:

AgNO3 is also highly soluble in water. Ionic means that the compound is composed of ions.

PLS HELP!!! i have no idea what this could be

Answers

Answer:

121.5g

Explanation:

from the equation:

2mol of Al react to give 3 mol of Zn

i.e 81g of Al will give 3×81/2 = 243/2 = 121.5g

CO2 + H2O --> C2H2 + O2

Answers

Answer:

C2H2 + 5 O2 = 4 CO2 + 2 H2O

Add / Edited: 27.09.2014 / 25.01.2015

Evaluation of information: 5.0 out of 5 / number of votes: 2

Source: https://chemiday.com/en/reaction/3-1-0-339

Explanation:


As you climb through the upper stratosphere, the temperature: increases decreases in constant

Answers

Answer:

It increases.

Explanation:

I hope this helps.

Answer:

Increases

Explanation:

Hope this helps :)

If I combine atoms then I must be performing which process?

A) Radiation Reaction

B) Strong Force

C) fission

D)Fusion

Answers

the answer is fusion. hope this helps!

Answer:

D: fussion

Explanation:

The process called nuclear fussion.

for example, four hydrogen atoms combine in a nuclear fussion reaction to form one helium atom.

Which type of fertilization is common with animals that live in the water?
1. external fertilization
2. sexual
3. internal fertilization
4. asexual

Answers

External fertilization in animals usually occurs in water or in damp areas in a process called spawning.

The answer for this would be the first one external fertilization

Match the special cases of each gas law with its description. A law may be used more than once. In the equations, K is a constant.

A. Boyle's law
B. Charles's law
C. Avogadro's law
D. Dalton's law

____ P1 V1 = P2 V2
____ V/T = k
____ V1 / T1 = V2 / T2
____ V = kn
____ PV = k
____ Ptotal = P1 + P2 + P3 + .​

Answers

The special cases of gas laws and its description includes:

A. Boyle's law: P1 V1 = P2 V2

B. Charles's law: V/T = k or V1 / T1 = V2 / T2

C. Avogadro's law: V = kn

D. Dalton's law: Ptotal = P1 + P2 + P3 + .

What is gas law?

Gas laws are laws that relate a gas's pressure, volume, and temperature. Boyle's law, named after Robert Boyle, states that the pressure P of a gas varies inversely with its volume V at constant temperature, or PV = k, where k is a constant. Charles' law is named after J. -A. -C.

They also include; Gay-Lussac's Law, Avogadro's Law and Dalton's law of partial pressures.

Learn more on gas laws here: https://brainly.com/question/25290815

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What is the molar mass of methane (CHA)?
A. 16.05
grams
O B. 13.02 grams
O C. 49.05 grams
O D. 10 grams

Answers

It is letter A , 16.05

2H20 → 2H2 + O2
Type of reaction?

Answers

Answer:

Notice how the elements splitIt is a decomposition reaction I do exams and quizzes if ur interested

Which substance is the least toxic?
a. chlorine (LD50 = 850 mg/kg)
b. vitamin A (LD50 = 2000 mg/kg)
c. cola (LD50 = 140 mg/kg)
d. aspirin (LD50 = 200 mg/kg)

Answers

Answer:

I believe it's D. I searched up a lethal table chart and it states Aspirin is even more toxic than chlorine. As for the other two, it didn't specifically state it was toxic with one dose - meaning you have to take more than one dose for toxicity to take effect.

Explanation:

___________ mL = 2.2 L

Answers

Answer:

2,200 mL I believe it is.

Answer:

2,200 is the answer of your question

Suppose you weigh the unknown substance on an electronic balance and find it has a mass of 445 grams. Analyzing the products of decomposition, you find that the masses of the elements in the sample are 232 grams of carbon, 58 grams of hydrogen, and 155 grams of oxygen. Finally, through further experimentation, you determine that the molar mass of the compound is 46.07 grams/mole.

Calculate the amount, in moles, of each component element in your substance. Use the periodic table to help you find the necessary molar masses.

____ moles of carbon

____ moles of hydrogen

____ moles of oxygen

Answers

Answer:

19.32 = moles of carbon

57.54 = moles of hydrogen

9.69 = moles of oxygen

Explanation:

232 g carbon × 1 mol C / 12.011 g C= 19.32 mol C

58 g hydrogen × 1 mol H / 1.008 g H = 57.54 mol H

155 g oxygen × 1 mol O / 15.999 g O = 9.69 mol O

How many moles of water are produced from the reaction of oxygen with four moles of propane (C3H8)? C3H8 + 5O2 --> 3CO2 + 4H2O

Answers

Answer:

Explanation:

The reaction is:

C₃H₈ + 5O₂  →  3CO₂  +  4H₂O

We see, that the equation is ballanced.

As we have data from only one reactant, we assume the other is in excess.

Ratio is 1:4 (stoichiometry). We solve this, by a rule of three:

1 mol of propane can produce 4 moles of water

Then, 4 moles of propane, may produce

( 4 . 4 ) /1 = 16 moles of water can be made.

Remember, we always have to work with the limiting reactant.

The useful energy a light bulb gives out is
(a). kinetic energy (b) chemical energy (c) light energy
science subject

Answers

Answer:

Light bulb gives light energy which is usefull

Answer:

(c) light energy

Explanation:

As bulb is used for giving light and hence the energy that it gives is light energy.

A screw decreases the amount of work done.

True
False

Answers

Answer:

tru

Explanation:

It would probably be False

16. Keesha performed a chemical reaction, and the products looked quite
different from the reactants. She knew the amount of matter had not
changed due to the law of conservation of mass. According to the law of
conservation of mass, what happens in a chemical reaction? *

Answers

Answer:

it's the third one

Explanation:

matter can't change, but mass can differ

Describe the natural processes which remove carbon dioxide from the atmosphere

Answers

Answer:

Explanation:

The process is photosynthesis as plants need carbon dioxide and humans need oxygen so plants release oxygen which humans breath/take in and plant/trees take in carbon dioxide which humans release.

The natural process which removes  carbon dioxide from the atmosphere is photosynthesis.

What is photosynthesis?

It is defined as a process by which plants and other photosynthetic organisms convert the light energy in to chemical energy  through the process of cellular respiration.

Some of the energy which is converted  is stored in molecules of carbohydrates like sugar and starches  which are made up of from carbon dioxide and water . Photosynthetic organisms which can perform photosynthesis  are algae and cyanobacteria. Photosynthesis is largely responsible for producing and maintaining the content of oxygen in earth's atmosphere.

The process begins with proteins absorbing light energy  which are called reaction centers and contain a green pigment which is called chlorophyll . In plants ,these pigments are present inside organelles called chloroplasts while in bacteria they are present in plasma membrane.

Learn more about photosynthesis,here:

https://brainly.com/question/29764662

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Hold the slides for observation

Answers

What is this

Explanation

Chemistry question on enthalpy HELP!!!!

Answers

Answer: The enthalpy change for this reaction is, -803 kJ

Explanation:

The balanced chemical reaction is,

[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]

The expression for enthalpy change is,

[tex]\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]

[tex]\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+(n_{H_2O}\times \Delta H_{H_2O})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{CH_4}\times \Delta H_{CH_4})][/tex]

where,

n = number of moles  

Now put all the given values in this expression, we get

[tex]\Delta H=[(1\times -394)+(2\times -242]-[(2\times 0)+(1\times -75)][/tex]

[tex]\Delta H=-803kJ[/tex]

Therefore, the enthalpy change for combustion of methane is, -803 kJ

How many elements are in (NH4)3PO4

Answers

Answer:

4

Explanation:

There are 4 different elements in the compound (N, H, P, O) but if you want to count the number of each element then the answer is different.

In NH4, theres 1 N and 4 H, but since there are 3 NH4s then u have 3 N and 12 H. There's 1 P and 4 Os as well.

Added together u have 3 + 12 + 1 + 4 = 20 elements in total.

hope this helps!

it’s four, the answer is four

Help pleaseedeeeeeeeeeeeeeeee

Answers

Answer:

the answer to this question here is A

Explanation:

trust me

Answer:

Acid and Salt

Explanation:

Common hydrogen compounds

Hydrogen combines with other elements, forming a number of compounds, including common ones such as water (H2O), ammonia (NH3), methane (CH4), table sugar (C12H22O11), hydrogen peroxide (H2O2) and hydrochloric acid (HCl), according to Jefferson Lab.

blance: Mg + HNO2 → Mg(NO2)2 + H2

Answers

Explanation:

Mg + 2HNO2 → Mg(NO2)2 + H2

Answer:

Mg + 2HNO2 → Mg(NO2)2 + H2

Explanation:

how many grams of H2O are in 3.00 moles of H2O?​

Answers

Answer:

mole=mass/molarmass

Explanation:

molar mass of h2o=18

I need help with question 4!!!!!!!

*Please choose correctly*

Thank youuuu

Answers

Answer:

hshzjndbejkxn. znkskakannamzm msk

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