Answer:
Average atomic mass = 79.9 amu.
Explanation:
Given data:
Average atomic mass of Bromine = ?
Atomic mass of 1st isotope = 78.92 amu
Relative abundance of 1st isotope = 50.69%
Atomic mass of 2nd isotope = 80.92 amu
Relative abundance of 1st isotope = 49.31%
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (50.69×78.92)+(80.92×49.31) /100
Average atomic mass = 4000.45 + 3990.16 / 100
Average atomic mass = 7990.61 / 100
Average atomic mass = 79.9 amu.
if the atomic mass is 14 and the atomic number is 7,how many neutrons do you have?
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)
Which of the following is a scientific question?
O A. Who made the first plant-hardiness zone map?
O B. Which plants are sold by my local nursery?
O c. Which kind of flowers should I plant in my garden?
O D. How does gravity affect the growth of plant roots?
explain why the reaction between lead (II) nitrate and concentrated sulphuric (VI) acid starts and stops immediately?
Answer:
The reaction produces insoluble lead (II) sulphate which coats the surface of lead (II) nitrate [Pb(NO3)]
Construct the chemical formulas for the ionic compounds.
Ionic compounds are formed from metal and non-metal elements
Further explanationThe 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
The volume of an object is 55mL in this city is 30g/mL. what is its mass
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!
We can change the substance chemically by
freezing it.
True or false
need helpppppp hurry pls, i just really need help
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
1. Find the number of protons, neutrons, electrons and electronic structure of flourine 919F.
2. Write the chemical formula of following compound.
Magnesium hydroxide
3. Balance the following equation
_H2 + _O2 --------> __H2O
1. ₉¹⁹F
2. Mg(OH)₂
3. 2H₂ + O₂ ⇒ 2H₂O
Further explanation1. 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
someone help me please i’ll give brainly
Answer:
b
Explanation:
i looked it up on Google
What charges would an atom of Cesium and Radium form based on the octet rule
Answer:
1+
Explanation:
Hope this helped!
Which of the following most likely happens when thermal energy is removed from a chemical reaction?
Answer:
fewer collisions occur between particles or lowering the temperature
Explanation:
what is the element for I am a metal and I have 6 Neutrons. PLEASE ANSWER TO MY QUESTION QUICKLY!!!!
Answer:
carbon-12
Explanation:
carbon 6/12 isotope has 6 neutrones and it is considered as a metal.
The rate of a chemical reaction would be decreased by
Answer:
The tempreature???
Explanation:
Colder tempreatures lead to a slower chemical reaction and warmer tempreatures lead to a faster chemical reaction.
Which best explains why aluminum is a nonrenewable resource?
A)It cannot be quickly replaced.
B)It is expensive to process.
C)It conducts electricity.
D)It is useful to humans.
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.)
2. How can glass be a liquid if it's so hard?
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.
how to know the unknown metal in flame test
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
Which of these ions has the correct charge?
O2-
B2+
P2-
Li2+
Answer:
02- i think your welcome hope it helps
Use your answers from questions 1–3 as the basis for the first section of your lab report. This section provides your reader with background information about why you conducted this experiment and how it was completed. Outline the steps of the procedure in full sentences. It also provides potential answers (your hypothesis/es) relative to what you expected the experiment to demonstrate. This section should be 1–3 paragraphs in length.
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:
The electronegativity values of carbon, hydrogen, and nitrogen are compared in the table.
Comparison of
Electronegativity
Element Electronegativity
Carbon
2.5
Hydrogen 2.1
Nitrogen 3.0
Which of the following statements is true about the strength of the intermolecular forces in CH4 and NH3? (4 points)
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.
This strong interaction is absent in methane which has just dipole - dipole attraction.The strength of the hydrogen bond depends on the electronegativity of the combining atoms.
To soften cloths in the wash it is recommended to use 2.0 g of sodium borate per liter of water. If a filled washing machine holds 10 L of water and the correct amount of sodium borate per liter is added, what is the concentration in percent mass/volume of the solution?
% m/v of the solution = 0.2%m/v
Further explanation[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]
A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is
(1) 1 (3) 12
(2) 11 (4) 23
Answer:
1
Explanation:
What is the total number of grams of a 32-gram sample of 32P remaining after 71.5 days of decay?
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.
Initial mass = 32 g Half life = 14.3 daysAfter 14.3 days ;
32 / 2 = 16 gramsAfter 14.3 × 2 = 28.6 days :
16/2 = 8 gramsAfter 14.3 × 3 days = 42.9 days :
8 / 2 = 4 gramsAfter 14.3 × 4 days = 57.2 days :
4 /2 = 2 gramsAfter 14.3 × 5 days = 71.5 days :
2 /2 = 1 gram.Hence, the mass of the sample left after 71.5 days would be 1 gram.
Learn more : https://brainly.com/question/18766174
How is the process of photosynthesis essential to sustaining life on Earth?
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
As the frequency decreases the wavelength...
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.
A car is traveling at 50mph. How long will it take the car to travel 300 miles?
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
What product(s) are formed during this chemical reaction? (There will be two correct answers)
Ca + Na3PO3 rightwards arrow
CaNaPO3
Ca3(PO4)2
Ca2(PO4)3
Ca(PO3)2
Na
Na3
CaNa
No Reaction
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.
What’s the answer????
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.
If, in the reaction below, 49 grams of Fe3O4 produces a 78.25% yield of Fe. How many grams are produced?
Really need help on this please, I’ll give brainliest!!
A sample of CO2 weighing 86.34g contains how many molecules?
Answer:
1.181 × 10²⁴ molecules CO₂
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.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
Which screw would create a strong hold?
A: The screw with 9 wraps.
B: The screw with 2 wraps.
C: The screw with 10 wraps.
D: The screw with 6 wraps.
Answer:
The screw with 10 wraps is the correct answer
Explanation:
The screw with 6 wraps would create a strong hold.
What do you mean by screw?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.
To learn more about Screw, refer to the below link:
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