7. Calculate the average atomic mass of bromine. One isotope of bromine has an atomic mass of 78.92amu and a relative abundance of 50.69%. The other major isotope of bromine has an atomic mass of 80.92amu and a relative abundance of 49.31%.

Answer:

carbon-12

Explanation:

carbon 6/12 isotope has 6 neutrones and it is considered as a metal.

Answer:

The tempreature???

Explanation:

Colder tempreatures lead to a slower chemical reaction and warmer tempreatures lead to a faster  chemical reaction.

Answer:

1 g

Explanation:

The following data were obtained from the question:

Original amount (N₀) = 32 g

Time (t) = 71.5 days

Half-life of phosphorus (t½) = 14.3 days

Amount remaining (N) =?

Next, we shall determine the rate of disintegration. This can be obtained as follow:

Half-life of phosphorus (t½) = 14.3 days

Decay constant (K) =?

K = 0.693 / t½

K = 0.693 / 14.3

K = 0.0485 /day

Finally, we shall determine the amount remaining as illustrated below:

Original amount (N₀) = 32 g

Time (t) = 71.5 days

Decay constant (K) = 0.0485 /day

Amount remaining (N) =?

Log (N₀/N) = Kt/2.303

Log (32/N) = 0.0485 × 71.5 / 2.303

Log (32/N) = 3.46775 / 2.303

Log (32/N) = 1.5058

Take the antilog of 1.5058

32/N = antilog (1.5058)

32/N = 32.05

Cross multiply

32 = N × 32.05

Divide both side by 32.05

N = 32 / 32.05

N = 0.998 ≈ 1 g

Thus, the amount remaining after 71.5 days is approximately 1 g.

The half-life of a radioactive substance refers to the time taken for the substance to Decay to half of its initial size. Hence, the mass of the substance left after 71.5 days is 1 gram.

After 14.3 days ;

After 14.3 × 2 = 28.6 days :

After 14.3 × 3 days = 42.9 days :

After 14.3 × 4 days = 57.2 days :

After 14.3 × 5 days = 71.5 days :

Hence, the mass of the sample left after 71.5 days would be 1 gram.

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Answer:

6 hours

Explanation:

If it is traveling at 50mph and needs to reah 300 miles, to figure this problem out you would want to divide 300 by 50 to get 6 hours. So it will take six hours until the car travels 300 miles

Hope this helps.

Answer: A car travels at a rate of 50 miles per hour. how long will it take the car to travel 300 miles?

Explanation: .

Applying the distance formula:

d = rt

where

d is distance (300 miles)

r is rate (50 mph)

t is time (hours)

.

300 = 30t

300/30 = t

10 hours = t

Answer:

Mass = 1650g

Explanation:

30g per mL is the density I suppose...

Solve for m!

30g/mL = m/55mL

Multiply by denominator to get numerator!

30* 55 =1650g

m = 1650g

Brainliest Appreciated!

Answer:

C. CH₄ is less than NH₃ because the NH bond is more polar than the CH bond

Explanation:

The intermolecular forces between ammonia is far stronger than for methane. Between the molecules of ammonia we have the presence of hydrogen bonds. This bond is absent in methane.

Hydrogen bonds are one of the strongest intermolecular forces. It is as a result of the electrostatic attraction between the hydrogen atom of one molecule and the electronegative atom N, O and F of another molecule.

The strength of the hydrogen bond depends on the electronegativity of the combining atoms.

Answer:

Increase

Explanation:

Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

Explanation:

The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light

Answer: 7 neutrons

Explanation: Atomic number refers to the number of protons in the nucleus of the atom. Also you can treat atomic mass as how many particles (protons and neutrons) are in the nucleus of the atom. So for this problem:

14 particles - 7 protons = 7 neutrons (and we know all that's left over is neutrons because we subtracted all the protons)

Explanation:

Glass is not a liquid in the strictest sense of the word. But it is also not a standard solid. The chemistry of glass is complex and research is ongoing, but the current consensus is that glass is a phase of matter all its own, known as an "amorphous solid". Scientists refer to any amorphous solid as a "glass". Glass transitions are highly complex and cannot be treated in the same way as traditional phase transitions.

Answer:

It's a liquid state before its cooled.

Answer:

The reaction produces insoluble lead (II) sulphate which coats the surface of lead (II) nitrate  [Pb(NO3)]

Answer:

Explanation:

Photosynthesis is important to living organisms because it is the number one source of oxygen in the atmosphere. Without photosynthesis, the carbon cycle could not occur, oxygen-requiring life would not survive and plants would die. ... The importance of photosynthesis in our life is the oxygen it produces

Answer:

fewer collisions occur between particles or lowering the temperature

Explanation:

Answer:

Ca3(PO4)2 and Na

Explanation:

The reaction equation is;

3Ca + 2Na3PO3 -------> Ca3(PO3)2 + 6Na

We must remember that calcium is above sodium in the electrochemical series. This implies that calcium can displace sodium from its solution. Calcium has a reduction potential of -2.87 V while sodium has a reduction potential of -2.71 V. The ion with the more negative reduction potential can easily displace the other in aqueous solution.

This explains why the reaction above is possible.

Answer:

6.8 mole of O₂

Explanation:

Given expression:

       2H₂   +   O₂   →   2H₂O

Number of moles of H₂ = 13.6moles

Unknown:

Number of moles of O₂  = ?

Solution:

In the given problem, we are to find the number of moles of oxygen gas that will use up 13.6mole of hydrogen gas;

 From the reaction equation;

             2 mole of H₂ will completely react with 1 mole of O₂

         13.6 moles of H₂ will completely be used up by [tex]\frac{13.6}{2}[/tex] mole of  O₂

                                                                                        = 6.8 mole of O₂

Answer:

1+

Explanation:

Hope this helped!

1. ₉¹⁹F

2. Mg(OH)₂

3. 2H₂ + O₂ ⇒ 2H₂O

1. Fluorine, atomic number : 9 , mass number = 19

Symbol : ₉¹⁹F

protons=electrons=atomic number = 9

neutrons = mass number - atomic mass

[tex]\tt n=19-9=10[/tex]

Configuration : [He] 2s² 2p⁵

2. Magnesium hydroxide is an ionic compound and is a strong base consisting of 2 ions:

Positive ion: Magnesium: Mg²⁺

negative ion: Hydroxide: OH⁻

The charges of the two are crossed, so that the compound becomes:

Mg(OH)₂

3. Reaction :

H₂ + O₂ --------> H₂O

give coefficient :

aH₂ + bO₂ --------> H₂O

H, left = 2a, right 2⇒2a=2⇒a=1

O, left = 2b, right 1⇒2b=1⇒b=0.5

Reaction becomes :

H₂ + 0.5O₂ --------> H₂O x 2

2H₂ + O₂ --------> 2H₂O

Answer:

1.181 × 10²⁴ molecules CO₂

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

86.34 g CO₂

Step 2: Identify Conversion

Avogadro's Number

Molar Mass of C - 12.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of CO₂ - 12.01 + 2(16.00) = 44.01 g/mol

Step 3: Convert

[tex]86.34 \ g \ CO_2(\frac{1 \ mol \ CO_2}{44.01 \ g \ CO_2} )(\frac{6.022 \cdot 10^{23} \ molecules \ CO_2}{1 \ mol \ CO_2} )[/tex] = 1.18141 × 10²⁴ molecules CO₂

Step 4: Check

We are given 4 sig figs. Follow sig fig rules and round.

1.18141 × 10²⁴ molecules CO₂ ≈ 1.181 × 10²⁴ molecules CO₂

Answer:

Greater

Greater

Explanation:

The amplitude of a wave is the height of the wave or the vertical displacement of the wave motion. We determine a wave amplitude usually by looking at the graph of the wave.

Amplitude is directly proportional to the energy of a wave. The higher the amplitude of a wave, the more its energy.

Frequency is the number of waves that passes a point at a particular instance of time. It is also directly proportional to the energy carried by a wave. The higher the frequency of a wave, the greater its energy.

Answer:

b

Explanation:

i looked it up on Google

% m/v of the solution = 0.2%m/v

[tex]\tt Percent~m/v=\dfrac{mass~solute(g)}{volume~solution(ml)}\times 100\%[/tex]

or

% m/v = g solute / 100 ml solution

Concentration : 2 g sodium borate / L water

For 10 L⇒20 g Sodium borate

[tex]\tt \%m/v=\dfrac{20~g}{10,000~ml}\times 100\%\\\\\%m/v=0.2\%[/tex]

Ionic compounds are formed from metal and non-metal elements

The chemical formula of compounds (especially ionic compounds) can be determined from the charge of each ion.

Determination of the ionic charge of the constituent elements of the compound can be seen from the electron configuration to achieve stability according to the octet rule

The charge of each ion will be crossed in the compound

Aluminum bromide

Al³⁺ + Br⁻ ⇒ AlBr₃

Magnesium bromide

Mg²⁺ + Br⁻ ⇒ MgBr₂

Sodium sulfide

Na⁺ + S²⁻ ⇒ Na₂S

Sodium nitride

Na⁺ + N³⁻ ⇒ Na₃N

Answer:

1-state what the lab is about, that is, what scientific concept (theory, principle, procedure, etc.) you are supposed to be learning about by doing the lab. You should do this briefly, in a sentence or two. If you are having trouble writing the opening sentence of the report, you can try something like: "This laboratory experiment focuses on X…"; "This lab is designed to help students learn about, observe, or investigate, X…." Or begin with a definition of the scientific concept: "X is a theory that…."                        2-give the necessary background for the scientific concept by telling what you know about it (the main references you can use are the lab manual, the textbook, lecture notes, and other sources recommended by the lab manual or lab instructor; in more advanced labs you may also be expected to cite the findings of previous scientific studies related to the lab). In relatively simple labs you can do this in a paragraph following the initial statement of the learning context. But in more complex labs, the background may require more paragraphs.

Explanation:

Answer: the correct answer is A

Explanation:

Answer:

A.) It cannot be quickly replaced.

Explanation:

Aluminum is extremely useful to humans but is semi-difficult to produce. Because of this, your answer will be numero uno. (Or A.)

Answer:

1

Explanation:

Answer:

The screw with 10 wraps is the correct answer

Explanation:

The screw with 6 wraps would create a strong hold.

The strongest member of the family of wood screws is a lag screw. It is a reliable and sturdy fastener that frequently has a square head or an externally powered hex drive.

In general, lag screws are significantly stronger and heavier than standard wood screws. They have a tapered point and coarse threads.

Thus, The screw with 6 wraps would create a strong hold.

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Answer:

02- i think your welcome hope it helps