Consider an element Z that has two naturally occurring isotopes with the following percent abundances: the isotope with a mass number of 19.0 is 55.0% abundant; the isotope with a mass number of 21.0 is 45.0% abundant. What is the average atomic mass for element Z?
Average atomic mass of Z = [mass]
Answer:
Average atomic mass = 19.9 amu
Explanation:
Isotopes can be defined as two or more forms of a chemical element that are made up of equal numbers of protons and electrons but different numbers of neutrons.
Generally, the isotopes of a chemical element have the same chemical properties because of their atomic number but different physical properties due to their atomic weight (mass number).
Given the following data;
Relative abundance of Z-19 = 55%
Relative abundance of Z-21 = 45%
Atomic mass of Z-19 = 19 amu
Atomic mass of Z-21 = 21 amu
To find the average atomic mass;
Average atomic mass = 19 * (55/100) + 21 * (45/100)
Average atomic mass = 19*0.55 + 21*0.45
Average atomic mass = 10.45 + 9.45
Average atomic mass = 19.9 amu
Therefore, the average atomic mass for element Z is 19.9 amu.
Easy Chem, Will Give brainliest
Answer:
3.94 L
Explanation:
From the question given above, the following data were obtained:
Mass of O₂ = 5.62 g
Volume of O₂ =?
Next, we shall determine the number of mole present in 5.62 g of O₂. This can be obtained as follow:
Mass of O₂ = 5.62 g
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mole of O₂ =?
Mole = mass / molar mass
Mole of O₂ = 5.62 / 32
Mole of O₂ = 0.176 mole
Finally, we shall determine the volume of 5.62 g (i.e 0.176 mole) of O₂ at STP. This can be obtained as follow:
1 mole of O₂ occupied 22.4 L at STP.
Therefore, 0.176 mole of O₂ will occupy = 0.176 × 22.4 = 3.94 L at STP.
Thus 5.62 g (i.e 0.176 mole) of O₂ occupied 3.94 L at STP
*14.
How many atoms of sulfur are in 0.75 moles of carbon disulfide?
10-14 is smaller than 107
Answer:
it is true because if you subtract 10 - 14 you will get -4 so it is less than 107.
Explanation:
Hope this helps!
PLEASE HELP I WILL MARK BRAINLIEST!
In a forest, lynx prey on rodents and birds in the summer. But because of rising temperatures, the birds in the forest have migrated to a cooler place. What effect will this migration have on the population of the rodents?
Because there are fewer birds, the lynx will prey on rodents, leading to a BLANK in their population. This scenario depicts BLANK competition.
Blank 1:
decline
rise
stagnancy
Blank 2:
apparent
direct
intraspecific
Answer:
The answer is decline and apparent
Explanation:
I took the test and got it right
Use the following equation to answer the questions below:
Be + 2HCl → BeCl2 + H2
Answers are rounded.. pick the closest to your answer.
What is the mass of beryllium required to produce 25.0g of beryllium chloride? g
What is the mass of hydrochloric acid required to produce 25.0g of beryllium chloride? g
What is the mass of hydrogen gas produced when 25.0g of beryllium chloride is also produced? g
Explanation:
The equation of the reaction is given as;
Be + 2HCl → BeCl2 + H2
What is the mass of beryllium required to produce 25.0g of beryllium chloride?
1 mol of Be produces 1 mol of BeCl2
Converting to mass;
Mass = Molar mass * Number of moles
9.01g of Be produces 79.92g of BeCl2
xg of Be produces 25g of BeCl2
Solving for x;
x = 25 * 9.01 / 79.92
x = 2.82 g
What is the mass of hydrochloric acid required to produce 25.0g of beryllium chloride? g
Converting 25.0g of beryllium chloride to moles;
Number of moles = Mass / Molar mass
Number of moles = 25 / 79.92 = 0.3128 mol
2 mol of HCl produces 1 mol of BeCl2
x mol of HCl would produce 0.3128 mol of BeCl2
solving for x;
x = 0.3128 * 2 = 0.6256 mol
Converting to mass;
Mass = 0.6256 * 36.5 = 22.83 g
What is the mass of hydrogen gas produced when 25.0g of beryllium chloride is also produced? g
25g of BeCl2 = 0.3128 mol of BeCl2
From the equation;
1 mol of H2 is produced alongside 1 mol of BeCl2
This means;
0.3128 mol of H2 would also be produced alongside 0.3128 mol of BeCl2
Mass = Number of moles * Molar mass
Mass = 0.3128mol * 2.0159 g/mol = 0.6306 g
Given the following equation formats, which form matches a single replacement
reaction?
O AB + CD → AD + CB
O A+B → AB
O A + BC → AC + B
O AB → A+B
Answer:
The answer is c. A + BC → AC + B
When a metal reacts with oxygen gas what is the product formed
Answer:
Metal + Oxygen -> Metal Oxide
Explanation:
It's pretty self-explanatory. However, let me show you an example:
Iron + Oxygen -> Iron Oxide
Iron rusts. When iron rusts, it comes in contact with air to form Iron Oxide, which is rust itself.
In matrix form structure PVC stands for what?
Answer:
polyvinyl chloride
Explanation:
what type of energy is playing the piano
A.light
B. Thermal
C.electrical
D.mechanical
E.sound
Answer:
E sound
Explanation:
3. Consider the reaction of methane, CH4, burning in the presence of oxygen at constant pressure. Given the following equation, how much heat could be obtained by the combustion of 8.0 grams CH4? Given the thermochemical equation: CH4(g)+2O2→CO2(g)+2H2O(l); ΔH0=890.3kJ;
Answer: 445.15 kJ of heat could be obtained by the combustion of 8.0 grams [tex]CH_4[/tex]
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} CH_4=\frac{8.0g}{16.04g/mol}=0.50moles[/tex]
The given thermochemical equation is:
[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex] [tex]\Delta H=890.3kJ[/tex]
According to stoichiometry :
1 mole of [tex]CH_4[/tex] on combustion produce heat = 890.3 kJ
Thus 0.50 moles of [tex]CH_4[/tex] on combustion produce heat =[tex]\frac{890.3}{1}\times 0.50=445.15kJ[/tex]
Thus 445.15 kJ of heat could be obtained by the combustion of 8.0 grams [tex]CH_4[/tex]
Does anyone know how to do this
Answer:
Explanation:
1-butanol has 4 carbon atoms with an OH group at the first carbon atom.
Dichlorodifluoromethane has 1 carbon atom with 2 chlorine atoms and 2 fluorine atoms.
Which product forms from a reaction between calcium (Ca) and phosphorus
(P)?
A. Ca2P3
B. Cap
C. CazP2
D. CaP2
Among these options, the correct formula for calcium phosphide is D. [tex]CaP_2[/tex]. Option D
The product formed from a reaction between calcium (Ca) and phosphorus (P) is calcium phosphide, which is represented by the chemical formula [tex]Ca_3P_2[/tex].
In the reaction between calcium and phosphorus, the calcium atom (Ca) donates two electrons to each phosphorus atom (P). This results in the formation of calcium ions (Ca2+) and phosphide ions (P3-). The ions combine to form the compound calcium phosphide ([tex]Ca_3P_2[/tex]).
The formula [tex]Ca_3P_2[/tex]indicates that three calcium atoms combine with two phosphorus atoms. The numerical subscripts are determined by the charges of the ions involved. Calcium, being a group 2 element, forms ions with a +2 charge (Ca2+), while phosphorus, being a group 15 element, forms ions with a -3 charge (P3-).
The product options provided are:
A. [tex]Ca_3P_2[/tex]
B. Cap
C. [tex]CazP_2[/tex]
D. [tex]CaP_2[/tex]
Among these options, the correct formula for calcium phosphide is D. [tex]CaP_2[/tex].
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Answer: Ca3P2
This is the answer!
Explanation:
A. Ca3P2
B. CaP2
C. Ca2P3
D. CaP
Part A
Consider the following neutral electron configurations in which n has a constant value. Which configuration
would belong to the element with the most negative electron affinity, Eea?
View Available Hint(s)
a 2s2
b 2s²2p2
c 2s²2p5
d 2s²2p6
Answer:
c. 2s2 2p5
Explanation:
2s2 2p5 has 7 valence electrons and only needs one electron to complete the octet. This element will be the most electronegative.
How can we identify patterns of volcanic eruptions?
which part of the red blood cells can you find hemoglobin
Answer:
The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million of these hemoglobin molecules.
Explanation:
hope this helps(;
Which has the least molecular kinetic energy?
water molecules in ...
A. a cloud
B. the ocean
C. Frozen pond
D. Pot of boiling water
1.5 atm is the same pressure as... (1 atm
760 mmHg)
1100 mmHg
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Gas Laws
PressureStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 1.5 atm
[Solve] mmHg
Step 2: Identify Conversions
1 atm = 760 mmHg
Step 3: Convert
[DA] Set up: [tex]\displaystyle 1.5 \ atm(\frac{760 \ mmHg}{1 \ atm})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1140 \ mmHg[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
1140 mmHg ≈ 1100 mmHg
Which of the following organisms carry out photosynthesis?
WS 3.5 more Lewis structures
What are the reactants in the following reaction?
2FeS + 302 → 2FeO + 2502
iron (II) sulfide and oxygen
iron (II) sulfide and iron (II) oxide
oxygen and sulfur dioxide
iron (11) oxide and sulfur dioxide
Answer:
Iron (II) sulfide and oxygen
Name an example of a molecule
Answer:
N2 (nitrogen) O3 (ozone) CaO (calcium oxide) C6H12O6 (glucose, a type of sugar)
Answer:
dihydrogen monoxide
dinitrogen monosulfide
Which of the following statements about maintaining a fitness program is ture?
Answer:
im sorry but you havent posted the pic
Explanation:
Which two statements about redox reactions are true?
A. Double-replacement reactions are redox reactions.
B. Acid-base reactions are redox reactions.
C. One type of atom is oxidized and another is reduced.
D. Electrons are transferred from one atom to another.
SUBMIT
Answer:
C. One type of atom is oxidized and another is reduced
D. Electrons are transferred from one atom to another
Explanation:
just took the test, i hope this helps!!
have a nice day and take care of yourself!! :))
One type of atom is oxidized and another is reduced and Electrons are transferred from one atom to another. Therefore, the correct options are options C,D.
What is redox reaction?Any chemical process in which a participating chemical species' oxidation number changes is known as an oxidation-reduction reaction, often known as a redox reaction. The phrase refers to a broad range of processes. Numerous oxidation-reduction processes are as frequent and well-known as fire, metal corrosion and disintegration, fruit browning, respiration, and photosynthesis—basic life processes.
The combined processes of oxidation and reduction are known as redox reactions due to their complimentary nature. The oxidising agent is the reactant that causes the oxidation, while the reducing agent itself reduces this reagent. One type of atom is oxidized and another is reduced and Electrons are transferred from one atom to another.
Therefore, the correct options are options C,D.
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make a prediction about the relationship between electrons and molecular shapes
Answer:
★ Molecular geometry is described by VSEPR theory, which basically states that electron pairs around a central atom will repel each other, and get as far apart as possible, in three dimensions.
Explanation:
Hope you have a great day :)
Calculate the mass of chromium produced from 50g of Cr2O3.
Answer: 34 gram of chromium produced from 50g of [tex]Cr_2O_3[/tex]
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Cr_2O_3=\frac{50g}{152g/mol}=0.33moles[/tex]
The decomposition of [tex]Cr_2O_3[/tex] follows the equation :
[tex]2Cr_2O_3\rightarrow 4Cr+3O_2[/tex]
According to stoichiometry :
2 moles of [tex]Cr_2O_3[/tex] produce = 4 moles of [tex]Cr[/tex]
Thus 0.33 moles of [tex]Cr_2O_3[/tex] will produce=[tex]\frac{4}{2}\times 0.33=0.66moles[/tex] of [tex]Cr[/tex]
Mass of [tex]Cr=moles\times {\text {Molar mass}}=0.66moles\times 52g/mol=34g[/tex]
Thus 34 gram of chromium produced from 50g of [tex]Cr_2O_3[/tex]
give the name of the method used to extract aluminium
When a large rock falls down a slope and breaks into small pieces, this is called _____________ _______________.
Group of answer choices
Answer: Mechanical weathering
Explanation:
Mechanical weathering breaks rocks into smaller pieces
How is conservation of mass illustrated in this simulation? Explain your answer.
Answer:
Do part by part
Explanation:
How many grams are in 6.60 moles of ZnO?
Answer:
6.60 moles of ZnO have 537,108 g.
Explanation: