Answer:
88
Explanation:
The ion has a charge of 2+, therefore the number of neutrons it possess is 86+2
which equals 88
The element X having a mass number of 230 and has 86 electrons is radium and has 142 neutrons.
An atom is composed basically of electrons, protons and neutrons. In a neutral atom, the number of protons and electrons are equal. The number of neutrons is the difference between the mass number and the number of protons (atomic number).
Since we know that the ion of the element X has 86 electrons and the compound formed is XBr2, it then means that neutral X has 88 electrons.
The number of electrons in the neutral atom is the same as the number of protons or atomic number. An element can be identified by its atomic number. The element having atomic number 88 is radium.
The number of neutrons is obtained as;
Mass number - atomic number
230 - 88 = 142 neutrons
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Which of the following is the best definition of a physical property?
A. Tearing paper in half.
B. Something that can be observed or measured while changing the identity of the substance.
C. The ability of something to undergo a change or reaction.
D. Something that can be observed or measured without changing the identity of the substance.
Answer:
D.Something that can be observed or measured without changing the identity of the substance.
formula for soda glass
Answer:
composition of soda-lime glass is 73% SiO2 – 15% Na2O − 7% CaO − 4% MgO − 1% Al2O3 [129,132,133].
The Soda glass formula is SiO2, Na2O, CaO, Al2O3, K2O, SO3, MgO, Fe2O3, TiO2
Soda glass is a chemical compound that stands out for being the most widely used material to make windows, bottles, glasses, among others.
This compound is characterized by being chemically stable, reasonably hard, and extremely versatile because it can be recycled since it can be melted to make new products.
Its chemical formula is made up of other compounds such as:
SiO2, is Silicon OxideNa2O, is sodium oxideCaO, is calcium oxideAl2O3, is aluminum oxideK2O, is potassium oxideSO3, is sulfur oxideMgO, is magnesium oxideFe2O3, is iron oxideTiO2, is Titanium OxideAdditionally, the compounds found in the highest proportion in glass are SiO2 (74 atoms) and Na2O (13 atoms).
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In the laboratory, a volume of 100 mL of sulfuric acid (H2SO4) is recorded. How many g are there of the liquid if its density is 1.83 g / cm3?
Answer:
[tex]\large \boxed{\text{183 g}}[/tex]
Explanation:
[tex]\begin{array}{rcl}\text{Density} & = & \dfrac{\text{Mass}}{\text{Volume}}\\\\\rho & = &\dfrac{m}{V}\\\\1.83 \text{ g$\cdot$ cm}^{-3} & = & \dfrac{m}{\text{100 cm}^{3}}\\\\m & = & \text{183 g}\\\end{array}\\\text{There are $\large \boxed{\textbf{183 g}}$ of sulfuric acid.}[/tex]
It requires work to _____. A. stretch a spring only B. compress a spring only C. stretch or compress a spring
Answer:
C.
Explanation:
It requires work to stretch or compress a spring.
Answer:the answer is c
Explanation: i say that because with work you can do both of those things
1.) Given 30 grams of CO2, how many moles of CO2 would you have? How many individual molecules of CO2 is that?
2., Given 22 Grams of NaCl, How many moles of Nacl would you have? How many individual molecules of NaCl is that?
3.) Given 50 grams of ammonia NH3, How many moles of NH3 would you have? How many Molecules of NH3 is that?
Answer:
1a) .68 moles 1b)4.1E-23 molecules.
2a) .37 moles 2b) 2.27E-23 molecules
Explanation:
1a) CO2 is equal to 44 grams (C→12 grams,O→16 grams[·2]) .30g/44g is .68 moles.
1b) multiply 1A by advogadros number (6.022E-23)
2a) NaCl is 58 grams. 22/58 is .37 moles.
2b) multiply 2A by advogadros number.
you'd answer #3 the same way #1 and #2
The branch of science that deals with chemicals and bonds are called chemistry. The moles are units to calculate the quantity required to use the element.
The correct answer is mentioned below.
What are moles?The mole is the base unit of the amount of substance in the International System of Units (SI). It is defined as exactly 6.02214076×10^23 elementary entities which may be atoms, molecules, ions, or electrons.According to the question, the moles to the option is as follows:-
moles of 30 grams of CO2 is[tex]n =\frac{M}{M.M}\\ \\\frac{30}{44} \\\\=0.681\\\\[/tex]
The number of molecules is [tex]0.68 *6022*10^{23} =4.09496*10^{23[/tex].
2. moles of 22 grams of NaCl is
[tex]\frac{22}{44}\\ \\=0.5\\\\[/tex]
Molecules will be [tex]0.5*6.022*10^{23} = 3.011*10^{23}[/tex]
3. moles of 50-gram ammonia
[tex]\frac{50}{17} \\\\2.94\\[/tex]
The number of molecules is [tex]2.94*6.022*10^{23} = 1770*10^{23[/tex]
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Tìm hóa trị của Fe trong hợp chất : FESO4, FE2(SO4)3, FR(OH)2, FE(OH)3
Answer: Fe hóa trị II trong các hợp chất: FeSO4, Fe(OH)2
Fe hóa trị III trong các hợp chất: Fe2(SO4)3, Fe(OH)3
Explanation:
Which of the following is the formula for vanadium (II) oxide? Question 11 options: A) VO2 B) VO C) V2O3 D) V2O5
Answer: A. ( VO2)
Explanation:
Answer:
B) VO
Vanadium(II) oxide is the inorganic compound with the idealized formula VO.
Question 2 of 10
How might the government make sure scientific research is done in an ethical
way?
A. By encouraging scientists to perform within their own ideas of
right and wrong
B. By letting public opinion determine what is ethical in scientific
research
C. By allowing scientists to do what they think is best
D. By taking away research funds if certain ethical standards are not
met
Answer: D
Explanation:
[tex]64.000L-4000dL[/tex]
Answer:
4000dl / 10 = 400l
64L - 400L
-336L
what are some examples of mutation
What element is depicted by the following electron configuration:
(The electron configuration is in the image)
A. None of these
B. Oxygen
C. Chlorine
D. Sulfur
Explanation:
Your required answer is sulpher.
Hope it helps...
describe melting of a solid
Describe the reaction of an acid with an alkali.?
Your question has been heard loud and clear.
The reaction of an acid with an alkali is neutralization reaction. It is a neutralization reaction because , they both neutralize each other (means it makes them chemically inactive after reacting) and produce a salt , and maybe water too.
An example: hydrochloric acid + sodium hydroxide → sodium chloride + water
Thank you
it will neutralise because if you add both of them together with a matching Ph such as 5 and 9 equally then it will neutralise and have a Ph of 7
could you please make me brainliest
Which of the following is the best definition of ethics?
A. The maintenance of a stable internal environment
B. Response to external stimuli
C. A set of guidelines for fair conduct during an experiment
D. A multistep process whose last step controls what happens in an
earlier step
Answer:
C
Explanation:
I believe the answer is C.
How do I unscramble
kgiueneoseph
Answer:
d
Explanation:
Housekeeping is the answer :)
I hope this answer helps you out. Brainliest would be appreciated. Have a good day/night :).which of the following will show tyndall effect ?
a. salt solution
b. copper sulphate solution
c. starch solution
d. chalk powder in water
Answer:
Starch solution
Explanation:
Colloidal solutions show tyndall effect and starch solution is a colloidal solution.
11. Samantha was asked to measure out 10 g of salt in a lab. She mistakenly measures out 15 g instead. Calculate
the percent error. Make sure your answer has the correct number of significant figures!
Answer:
50%
Explanation:
Expected measurement required = 10g
Actual measurement observed = 15g
The percentage error is given as proportion the difference between the actual and expected measurement or values and the expected value value expressed as a percentage.
[(Actual - Expected) / Expected] × 100%
[(15 - 10) / 10)] × 100%
(5 / 10) × 100%
0.5 × 100%
50%
Therefore, the percentage error in the measurement is 50%
the mass of empty cylinder is 20 gram its mass when its filled completely with water is 30 gram and its mass when its filled completely with unknown liquid is 27 gram find the density of, the unknown liquid
Answer:
≈ 0.70 g/cm³ (answer rounded up to 2 decimal places)
Explanation:
The mass of empty cylinder is 20g
The mass of water filling the cylinder = 30g - 20g = 10g
The mass of unknown liquid filling the cylinder = 27g - 20g = 7g
Density of water = 997 kg/m³
Converting this density to g/cm³ we get;
1kg = 1000g , 1m³ = 1000000cm³
So density = [tex]\frac{997000}{1000000}[/tex] g/cm³ = 0.997 g/cm³
So the volume of water occupied by 10g is;
10 × 0.997 = 9.97 cm³
This volume is also occupied by 7g of the unknown liquid.
Density = mass/volume
Density of the unknown liquid = 7g ÷ 9.97cm³ = 0.702106319 g/cm³ ≈ 0.70 g/cm³ (answer rounded up to 2 decimal places)
Question 2 of 10
How might the government make sure scientific research is done in an ethical
way?
A. By encouraging scientists to perform within their own ideas of
right and wrong
B. By letting public opinion determine what is ethical in scientific
research
C. By allowing scientists to do what they think is best
D. By taking away research funds if certain ethical standards are not
met
Answer:
C I think. If I am wrong please correct me.
Explanation:
A student conducts an experiment to determine how the temperature of water affects the time for sugar to dissolve. In each trial, the student uses a different amount of water and a different temperature of water. What is wrong with this experimental design? A.The student changed more than one independent variable. B.The student did not change enough independent variables. C.The student needs to perform more trials. D.The student does not have a dependent variable.
What is wrong with the experimental design is that the student changed more than one independent variable.
WHAT AN EXPERIMENT SHOULD CONTAIN?
An experiment is a procedural method of solving a scientific problem or answering a scientific question. An ideal experiment should contain two variables namely: independent variable and dependent variable. Dependent variable: This is the variable that the experimenter measures in the experiment. The dependent variable responds to changes made to the independent variable. Independent variable: This is the variable that is manipulated in an experiment in order to bring about a response.In the experiment conducted by the student in this question in order to determine how the temperature of water affects the time for sugar to dissolve. The independent variable is the DIFFERENT TEMPERATURE OF WATER while the dependent variable is the TIME TAKEN FOR SUGAR TO DISSOLVE.
N.B: An experiment should have only one independent variable and all other variables should be kept constant. This is to have a reliable result.
However, this student used two independent variables (temperature and amount of water) for the experiment, which is wrong for the experimental design.Therefore, the fact that the student changed more than one independent variable is wrong for the experimental design.
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Answer:
The student changed too many variables.
Explanation:
in k-12 took the quiz
Os subníveis mais energéticos de um dado átomo são: ...4s2 3d10 4p5 a) indique o seu número atomico b) quantos electrões de valência apresenta esse átomo c) a que família pertence?
Answer:
A. 35
B. 7
C. halogênios
Explanation:
Aqui, para responder a essa pergunta, precisaremos conhecer o elemento particular em questão.
..... 4s ^ 2 3d ^ 10 4p ^ 5 significa que está a cinco elétrons da configuração eletrônica do último elemento na primeira camada dos metais pesados.
O último elemento da 1ª série do elemento de transição é o zinco, portanto, como está a apenas 5 elementos de distância, o átomo de que estamos falando é o átomo de Bromo de Bromo.
A. O zinco tem um número atômico 30 e como o bromo está a 5 elementos de distância, seu número atômico é 35
B. Uma vez que pertence ao grupo halogênio, tem 7 elétrons de valência como o resto da família
C. Pertence à família dos halogênios
If you are designing an experiment, how will you determine your independent or dependent variable?
Answer:
The independent variable effects the dependent variable.
Explanation:
The independent variable Is what you change whereas the dependent variable would change because of that.
for example, the indipendent variable could be how much you water a plant in ml each day, and the dependent variable would be how tall each plant grown]s with that water doseage per day.
how much of the excess reactant remains unchanged?
how much N2 is formed? (in mol)
how much H2O is firmed? (in mol)
Answer:
1. The limiting reactant is H2O2.
2. The amount of excess reactant, N2H4 that remain unchanged is 11.15 moles.
3. 1.65 moles of N2.
4. 6.6 moles of H2O.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
N2H4 + 2H2O2 —> N2 + 4H2O
From the balanced equation above,
1 mole of N2H4 reacted with 2 moles of H2O2 to produce 1 mole of N2 and 4 moles of H2O.
1. Determination of the limiting reactant.
From the balanced equation above,
1 mole of N2H4 reacted with 2 moles of H2O2.
Therefore, 12.8 moles of N2H4 will react with = 12.8 x 2 = 25.6 moles of H2O2.
From the calculations made above, we can see that it will take a higher amount i.e 25.6 moles than what was given i.e 3.3 moles of H2O2 to react completely with 12.8 moles of N2H4.
Therefore, H2O2 is the limiting reactant and N2H4 is the excess reactant.
2. Determination of the excess reactant that remain unchanged.
The excess reactant is N2H4.
First, we shall determine the amount of the excess reactant that reacted. This is illustrated below:
From the balanced equation above,
1 mole of N2H4 reacted with 2 moles of H2O2.
Therefore, Xmol of N2H4 will react with 3.3 moles of H2O2 i.e
Xmol of N2H4 = (1 x 3.3)/2
Xmol of N2H4 = 1.65 moles
Therefore, 1.65 moles of N2H4 reacted.
Now, we shall determine the excess reactant that remain unchanged. This can be obtained as follow:
Amount of N2H4 given = 12.8 moles
Amount of N2H4 that reacted = 1.65 moles.
Amount of N2H4 that remain unchanged =?
Amount of N2H4 that remain unchanged = (Amount of N2H4 given) – (Amount of N2H4 that reacted = 1.65 moles)
Amount of N2H4 that remain unchanged = 12.8 – 1.65
Amount of N2H4 that remain unchanged = 11.15 moles.
3. Determination of the amount of N2 produced.
In this case, the limiting reactant will be used because it will give the maximum yield of N2 as all of it is used up in the reaction.
The limiting reactant is H2O2 and the amount of N2 produced can be obtained as follow:
From the balanced equation above,
2 moles of H2O2 reacted to produce 1 mole of N2.
Therefore, 3.3 moles of H2O2 will react to produce = (3.3 x 1)/2 = 1.65 moles of N2.
Therefore, 1.65 moles of N2 were obtained from the reaction.
4. Determination of the amount of H2O produced.
In this case, the limiting reactant will be used because it will give the maximum yield of H2O as all of it is used up in the reaction.
The limiting reactant is H2O2 and the amount of H2O produced can be obtained as follow:
From the balanced equation above,
2 moles of H2O2 reacted to produce 4 moles of H2O.
Therefore, 3.3 moles of H2O2 will react to produce = (3.3 x 4)/2 = 6.6 moles of H2O.
Therefore, 6.6 moles of H2O were produced from the reaction.
why do the aquatic plants not break down by water current?
Hòa tan hoàn toàn 10 gam hỗn hợp hai oxit CuO và Fe2O3 cần 100ml dung dịch HCl 3,5M. Khối lượng CuO và Fe2O3 có trong hỗn hợp ban đầu lần lượt là
Answer:
CuO+2HCl>h2o+CuCl2
fe203+6hcl->2fecl3+3h2O
gọi CuO, fe2o3 lần lượt là x,y
80x+160y=10
2x+6y=0.35
giải phương trình ta dc hai số x,y(tính phương trình kia ra)
cuo ban đầu sẽ là :60*x=z
fe203 ban đầu sẽ là :10-z=
Explanation:
HELP!!!!!!, I need this urgently!!!
Compare the properties of producer and water gas
Answer:
Producer gas and water gas contain carbon monoxide and hydrogen.
Describe how methane is
formed in terms of chemical bonding
13. Water is a polar compound because it exhibits _______
charges.
O A. negative
O B. positive
O C. opposite
D. neutral
Answer:
Opposite.
Water exhibits negative charge near hydrogen, positive near oxygen.
This is why it is OPPOSITE.
Let me know if this helps!
Water is a polar compound because it exhibits opposite charges. Therefore, option C is correct.
What is polar compound ?The term polar compound is defined as the compound with distinct regions of positive and negative charge, as a result of bonding with atoms such as nitrogen, oxygen, or sulfur.
Water is a polar compound because the covalent bonds between hydrogen and oxygen in the water molecule are polar in nature. Any molecule with lone pairs of electrons around the central atom is polar compound.
In water there are two atoms are present that are oxygen and hydrogen. Hydrogen has positive charge while oxygen has negative charge,
Thus, Water is a polar compound because it exhibits opposite charges, option C is correct.
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Sarah is in her chemistry lab doing an experiment. When she goes to take the mass of the chemical she is working with, she discovers that the balance is gone! Sarah knows the density of her chemical is 10 g/mL, and the volume is 5 mL. What is the mass of her chemical?
Answer:
Mass of chemical = 50 gram
Explanation:
Given:
Volume of chemical = 5 ml
Density of chemical = 10 g/mL
Find:
Mass of chemical
Computation:
Mass of chemical = Density of chemical × Volume of chemical
Mass of chemical = 10 × 5
Mass of chemical = 50 gram
1. If I have 3 identical books that all have a length of 25cm, a
width of 15cm, and are 11cm tall, what would be the volume of
all 3 books?
Answer:
12,375 cm³
Explanation:
v=l×w×h
Since there are 3 books the equation would then be
v=3(l×w×h)
v=3(25×15×11)
v=3(4,125)
v=12,375 cm³