A hypothesis is ______ to explain a set of observations.

1 one possible way
2 the correct method
3 a factual statement
4 a set of data ​

Number of Br atoms : 2.679 x 10²³

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

[tex]\tt mol=\dfrac{mass}{MW}[/tex]

Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements

[tex]\tt mass~Br=\dfrac{2.Ar~Br}{MW~CH_2Br_2}\times mass~CH_2Br_2\\\\mass~Br=\dfrac{2.80}{174}\times 38.7=35.59~g[/tex]

[tex]\tt \dfrac{35.59}{80}=0.445[/tex]

[tex]\tt 0.445\times 6.02\times 10^{23}=\boxed{\bold{2.679\times 10^{23}}}[/tex]

Answer:

By Newton's 2nd law, m*a=sum_of_forces where m is the mass and a the acceleration. Here there are two forces in opposed directions.

Thus 5*a=40-8=32 therefore a=32/5=6.4m^s/2

Answer:

The age of the earliest known human-like footprints is approximately 3000000 years.

Explanation:

Decay of isotopes is represented by the following ordinary differential equation:

[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)

Where:

[tex]\frac{dm}{dt}[/tex] - First derivative of mass with respect to time, measured in miligrams per year.

[tex]m[/tex] - Current mass of the isotope, measured in miligrams.

[tex]\tau[/tex] - Time constant, measured in years.

Now we proceed to obtain the solution of the differential equation:

[tex]\int\limits {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]

[tex]\ln m = -\frac{t}{\tau}+C[/tex]

[tex]m(t) = e^{-\frac{t}{\tau}+C }[/tex]

[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)

Where:

[tex]m_{o}[/tex] - Initial mass of the isotope, measured in miligrams.

[tex]t[/tex] - Time, measured in years.

[tex]\tau[/tex] - Time constant, measured in years.

We proceed to clear time within the formula presented above:

[tex]\ln \frac{m(t)}{m_{o}} = -\frac{t}{\tau}[/tex]

[tex]t = -\tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]

In addition, time constant can be found as a function of half-life:

[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)

If we know that [tex]t_{1/2} = 500000\,yr[/tex], [tex]m_{o} = 8\,mg[/tex] and [tex]m(t) = 0.125\,mg[/tex], the age of the earliest known human-like footprints is:

[tex]\tau = \frac{500000\,yr}{\ln 2}[/tex]

[tex]\tau \approx 721347.520\,yr[/tex]

[tex]t = -(721347.520\,yr)\cdot \ln \left(\frac{0.125\,mg}{8\,mg} \right)[/tex]

[tex]t \approx 3000000\,yr[/tex]

The age of the earliest known human-like footprints is approximately 3000000 years.

Answer:

Which has the longest wavelength?

✔ microwaves

x infrared

x visible

x X-rays

Which has the highest frequency?

✔ X-rays

x infrared

x microwaves

x visible

Explanation:

I apologize if this was a late answer or if this doesn't answer your original question, but hope this helps! :)

Answer:

Microwaves then X rays

Explanation:

Answer:

He and Ar

Explanation:

Answer and Explanation:

The galvanic cell is:

Cu(s)| Cu²⁺(aq)|| Cu⁺(aq)| Cu(s)

The first two species before the double bar (||) constitute the anodic half reaction (oxidation):

Cu(s) ⇒ Cu²⁺(aq) + 2 e-

The two species after the || constitute the cathodic half reaction (reduction):

Cu⁺(aq) + e- ⇒ Cu(s)

If we multiply the reduction half reaction by 2 (to obtain the same number of electrons than oxidation reaction) and then we add the two half reactions, we obtan the balanced equation:

Reduction (cathode) : 2Cu⁺(aq) +2 e- ⇒ 2Cu(s)

Oxidation (anode) :     Cu(s) ⇒ Cu²⁺(aq) + 2 e-

                                  ------------------------------------

Total equation:         2Cu⁺(aq) + Cu(s) ⇒ 2Cu(s) + Cu²⁺(aq)

Cu(s) is in both reactants side and products side, so we cancel that in both opposite sides to obtain:

2Cu⁺(aq) ⇒ Cu(s) + Cu²⁺(aq)

If we divide the balanced equation into 2, the smallest possible integer coefficient for Cu⁺(aq) is 1:

Cu⁺(aq) ⇒ 1/2 Cu(s) + 1/2 Cu²⁺(aq)

Answer:

Chemical Change

Explanation:

The explosion of fireworks is an example of chemical change. During a chemical change, substances are changed into different substances. In another words, the composition of the substance changes.

Answer:

it is C

Explanation:

I saw from Google. Hope it helps.

I cant get the full picture

sorry

Answer:

Yes, Magnesium

[tex]1 \: mol MgSO4 \: has \: 4 \: oxygens[/tex]

Thus ;

[tex]2 \: mols \: of \: should \: have \: 8 \: oxygens[/tex]

So the correct answer is (( 8 مول ))

Answer:D. 2857 joules

Explanation:

Not going to lie I guessed but got it right

According to specific heat capacity, 3596.208 joules of energy is required to heat 0.24 kg of lutetium from 296.2 K to 373.5 K.

Specific heat capacity is defined as the amount of energy required to raise the temperature of one gram of substance by one degree Celsius. It has units of calories or joules per gram per degree Celsius.

It varies with temperature and is different for each state of matter. Water in the liquid form has the highest specific heat capacity among all common substances .Specific heat capacity of a substance is infinite as it undergoes phase transition ,it is highest for gases and can rise if the gas is allowed to expand.

It is given by the formula ,

Q=mcΔT

Substitution in above formula gives, q= 0.24×154×97.3=3596.208 Joules.

Thus, 3596.208 joules of energy is required to heat 0.24 kg of lutetium from 296.2 K to 373.5 K.

Learn more about specific heat capacity,here:

https://brainly.com/question/1747943

#SPJ2

Answer:

First One And Third Pls Mark Brainlest

Explanation:

Answer:

Stars generate energy through nuclear fusion. Here's an easy explanation about how the process works. ... Stars spend most of their lives repetitively compressing two hydrogen atoms into a single helium atom – plus a lot of energy, which is released as light and heat.

The answer Is B;A chemical bond holds atoms together.

Answer:

Mg[tex]^+2[/tex]

Explanation:

Es el elemento que buscas.

Answer:

Its going to be D) In sigma bonds the electrons are in the space between the joined atoms and pi bonds above and below the joined atoms

Answer: Gases have the lowest density of the three, are highly compressible, and completely fill any container in which they are placed. Gases behave this way because their intermolecular forces are relatively weak, so their molecules are constantly moving independently of the other molecules present. Solids, in contrast, are relatively dense, rigid, and incompressible because their intermolecular forces are so strong that the molecules are essentially locked in place.

Explanation:

Answer:

Explanation:

The distance covered by an object given it's velocity and time taken can be found by using the formula

From the question

velocity = 35.0 mi/hr

time = 2455 s = 0.68 hr

We have

distance = 35 × 0.68

We have the final answer as

Hope this helps you

Answer:

C6H12O2

Explanation:

The first step in accurately deducing the structure/formula of the model is to count the number of carbon atoms, hydrogen atoms and oxygen atoms mentioned in the model. This gives the molecular formula of the compound.

Next, you look at there arrangement of atoms and bonds as stated in the model, this tells us the structure of the molecule and confirms the molecular formula initially deduced.

The structure of the compound is shown below.

Answer:

Your answer would be C6H12O2

Explanation: I hope I helped you :)

Answer:Rubidium and Strontium

Explanation:

Answer: A.En Hedu'Anna

Answer:

En Hedu’Anna!

Explanation:

Answer:

Equation:

Q = m•C•ΔT

Answer:

the brain

Explanation:

Answer:

The uncertainty principle, proposed in 1927 by German physicist Werner Heisenberg, states that the more precisely a particle's position is measured, the less precisely its momentum can be known, and vice versa. ... They wanted to measure the polarization, or orientation, of the photon.

Answer:

0.2007 nm

3.57 cm

0.01478 g

8280000 pg

Explanation:

1)200.7 pm

1 picometer is equal to 0.001 nanometer.

1 nm = 1000 pm

200.7 pm× 1 nm / 1000 pm  = 0.2007 nm

2)0.000357 hm

1 hectometer is equal to 10,000 centimeter.

1 hc = 10,000 cm

0.000357 hc× 10,000 cm / 1 hc = 3.57 cm

3) 14.78 mg

1 gram is equal to 1000 milligram.

1 g = 1000 mg

14.78 mg × 1 g/1000 mg = 0.01478 g

4)8.280 µg

1 microgram is equal to 10⁶ picogram.

1 µg = 1000000 pg

8.280 µg× 10⁶ pg/ 1µg = 8.280×10⁶ pg or 8280000 pg

Answer:

E. A conductor is needed for electricity to flow in a circuit.

Explanation:

Electric current can flow without a resistor, as in short circuit.

A short circuit is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance.

Without a switch, electricity can flow in a circuit, switch is only used to close or open the circuit.

Thus, the only correct option is  E

E. A conductor is needed for electricity to flow in a circuit.

Answer:

'*:*'

Explanation:

I know this looks weird, but

'= electron

*:* equals the nucleus, so 2 protons and 2 neutrons

and then '=electron

Answer: D. A 2 kg pot at 25C.

Explanation: