Answer:
64
Explanation:
mass number =proton + neutron
=30+34=64
A scientist observes several different fossils in a
rock layer. Based on this observation, which is
the best conclusion?
A. The fossils are composed of lava that cooled
around several organisms.
B. The fossils formed about the same time as the
rock layer in which they were found.
C. The fossils formed after heat and pressure
changed the type of rock in the rock layer.
D. The fossils are composed of the same material
as the organisms from which they formed.
A scientist observes several different fossils in a
rock layer. Based on this observation, which is
the best conclusion?
Answer:A. The fossils are composed of lava that cooled
A. The fossils are composed of lava that cooledaround several organisms.
B. The fossils formed about the same time as the rock layer in which they were found.
Explanation:That's the right answer but you can choose one.
#CARRYONLEARNING #STUDYWELLWhich body system or systems are affected by asthma?
Answer:
The lungs
Explanation:
Asthma is a disease that affects the airways of your lungs. With asthma, your airways' lining tends to always be in a hypersensitive state characterized by redness and swelling. Causing the airways to swell and, in severe cases, close completely off.
hope this helps, this should also probably be in biology:)
What is the density of lead (in g/cm^3 3 ) if a rectangular bar measuring 0.500 cm in height, 1.55 cm in width, and 25.00 cm in length has a mass of 220.9 g? Report the answer with the units of g/cm^3 3 and the proper number of significant figures. Numbers in bold count towards significant figures. Type your answer here with correct significant figures and units:
Answer:
Density = 11.4 g/cm³
Explanation:
Given data:
Density of lead = ?
Height of lead bar = 0.500 cm
Width of lead bar = 1.55 cm
Length of lead bar = 25.00 cm
Mass of lead bar = 220.9 g
Solution:
Density = mass/ volume
Volume of bar = length × width × height
Volume of bar = 25.00 cm × 1.55 cm × 0.500 cm
Volume of bar = 19.4 cm³
Density of bar:
Density = 220.9 g/ 19.4 cm³
Density = 11.4 g/cm³
A 2.912 g sample of a compounds containing only C, H, and O was completely oxidized in a reaction that yielded 3.123 g of water and 7.691 g of carbon dioxide. Determine the empirical formula and molecular formula of the compound if it has a molar mass of 100.1 g/mol.
Answer:
Explanation:
18 gram of water contains 2 g of hydrogen
3.123 gram of water will contain 2 x 3.123 / 18 = .347 g of hydrogen .
44 gram of carbon dioxide contains 12 g of carbon
7.691 gram of carbon dioxide will contain 12 x 7.691 / 44 = 2.1 g of carbon .
So the sample will contain 2.912 - ( .347 + 2.1 ) g of oxygen .
= .465 g of oxygen .
moles of Carbon = 2.1 / 12 = .175
moles of hydrogen = .347 / 1 = .347
moles of oxygen = .465 / 16 = .029
Ratio of moles of carbon , oxygen and hydrogen ( C,O,H )
= 0.175 : 0.029 : 0.347
= .175/ .029 : 1 : .347 / .029
= 6 : 1 : 12
So empirical formula = C₆H₁₂O
Let the molecular formula be [tex](C_6H_{12}O)_n[/tex]
molecular weight = n ( 6 x 12 + 12x 1 + 16)
= 100 n
Given 100 n = 100.1
n = 1
Molecular formula = C₆H₁₂O.
Container A holds 717 mL of an ideal gas at 2.80 atm. Container B holds 174 mL of a different ideal gas at 4.30 atm. Container A and container B are glass spheres connnected by a tube with a stopcock. Container A is larger than container B. If the gases are allowed to mix together, what is the resulting pressure
Answer:
3.09 atm
Explanation:
Given that:
Volume of container A = 717 mL
Pressure of container A = 2.80 atm
Volume of container B = 174 mL
Pressure of container B = 4.30 atm
Now, if the valve are being removed and the gases are allowed to mix together; then
The total final pressure can be calculated by using the formula:
[tex]P_f = \dfrac{P_AVA+P_BV_B}{V_A+V_B}[/tex]
[tex]P_f = \dfrac{2.80*717+4.30*174}{717+174}[/tex]
[tex]P_f = \dfrac{2007.6+748.2}{891}[/tex]
[tex]P_f = \dfrac{2755.8}{891}[/tex]
[tex]\mathbf{P_f =3.09 \ atm}[/tex]
The absence of the intermolecular attraction between the atoms or molecules is called an ideal gas. The pressure of the resultant mixture is 3.09 atm.
What is the relation between pressure and volume?The relationship between the pressure and the volume of the gas is given by Boyle's law which states the inverse proportionality relation with the volume.
Given,
The volume of container A = 717 mL
The volume of container B = 174 mL
The pressure of container A = 2.80 atm
The pressure of container B = 4.30 atm
The total final pressure of the ideal gas of the mixture is calculated by:
[tex]\begin{aligned} \rm P_{f} &= \rm \dfrac{P_{A}V_{A}+ P_{B}V_{B}}{V_{A}+V_{B}}\\\\&= \dfrac{2007.6 +748.2}{891}\\\\&= 3.09 \;\rm atm\end{aligned}[/tex]
Therefore, the total pressure of the mixture is 3.09 atm.
Learn more about pressure here:
https://brainly.com/question/13534890
which formula represents a molecule solid
Dry ice are the molecule which represent molecular solid. Hence option c is correct.
What are molecule?Molecules are defined as the lowest identifiable unit into which a pure material can be divided while maintaining its chemical makeup and attributes is made up of two or more atoms. When two or more atoms come together and form bonds with one another, a molecule is created. Each atom shares an electron when a bond is formed between them. A molecule is created as a result of a covalent bond.
Molecular solid are defined as composed of atoms or molecules joined by hydrogen bonds, London dispersion forces, and dipole-dipole forces. Solids made of molecules and held together by van der Waals forces are referred to as molecular solids. Examples include carbon dioxide, hydrogen, etc. Crystalline solids include ZnS. The ionic solid MgO is. Diamond is organized in a network.
Thus, dry ice are the molecule which represent molecular solid. Hence option c is correct.
To learn more about molecule, refer to the link below:
https://brainly.com/question/19922822
#SPJ6
Your question is incomplete, but probably your complete question was
Which of the following is an example of molecular solid?
a. Zinc sulphide
b. Magnesium oxide
c. Dry ice
d. Diamond
Smallest particle of a substance that can retain its properties & is
composed of one or more atoms *
O A. Atom
O B. Molecules
O C. Matter
O D. Everything
Answer:
Molecules
Explanation:
Which number should go in the blank?
- H₂ + O2 -> 2H₂O
O
2
3
1
How many grams are in 4.63 x 1024
molecules of CCl4?
Answer:
[tex]m=1,182.8g[/tex]
Explanation:
Hello!
In this case, since the relationship between molecules and mass is first analyzed via the Avogadro's number to compute the moles in the given molecules:
[tex]mol=4.63x10^{24}molec*\frac{1mol}{6.022x10^{23}molec}=7.69mol[/tex]
We now use the molar mass of carbon tetrachloride (153.81 g/mol) to obtain the required grams:
[tex]m=7.69mol*\frac{153.81g}{1mol} \\\\m=1,182.8g[/tex]
Best regards!
A chemist dissolves of pure potassium hydroxide in enough water to make up of solution. Calculate the pH of the solution. (The temperature of the solution is .) Be sure your answer has the correct number of significant digits.
Answer:
12.99
Explanation:
A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.
Step 1: Given data
Mass of KOH: 716. mg (0.716 g)Volume of the solution: 130. mL (0.130 L)Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
Question 3 (1 point)
Consider the following unbalanced chemical equation representing the combustion of methane, yielding carbon dioxide and water.
CH4 + O2 --> CO2 + H20
If you had burned 800 g of methane, how many moles of Carbon dioxide would be produced?
A)122.22
B)8
C)2200
D)100
E)670
F)750
G)50
Answer:
Im pretty sure its B
Explanation:
Answer:
G) 50 mol
Explanation:
Given data:
Mass of methane = 800 g
Number of moles of CO₂ produced = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of methane:
Number of moles = mass/molar mass
Number of moles = 800 g/ 16 g/mol
Number of moles = 50 mol
Now we will compare the moles of methane and carbon dioxide.
CH₄ : CO₂
1 : 1
50 : 50
if you are provided with 34.5 g iron (iii) chloride and 25.3 g sodium carbonate what is the limiting ractant
Answer:
Sodium carbonate, Na₂CO₃ is the limiting
Explanation:
We'll begin by writing the balanced equation for the reaction between iron (iii) chloride, FeCl₃ and sodium carbonate, Na₂CO₃.
This is illustrated below:
2FeCl₃ + 3Na₂CO₃ → Fe₂(CO₃)₃ + 6NaCl
Next, we shall determine the masses of FeCl₃ and Na₂CO₃ that reacted from the balanced equation. This can be obtained as follow:
Molar mass of FeCl₃ = 56 + (3×35.5)
= 56 + 106.5
= 162.5 g/mol
Mass of FeCl₃ from the balanced equation = 2 × 162.5 = 325 g
Molar mass of Na₂CO₃ = (2×23) + 12 + (3×16)
= 46 + 12 + 48
= 106 g/mol
Mass of Na₂CO₃ from the balanced equation = 3 × 106 = 318 g
SUMMARY:
From the balanced equation above,
325 g of FeCl₃ reacted with 318 g of Na₂CO₃.
Finally, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
325 g of FeCl₃ reacted with 318 g of Na₂CO₃.
Therefore, 34.5 g of FeCl₃ will react with = (34.5 × 318)/325 = 33.76 g of Na₂CO₃.
From the calculations made above, we can see clearly that it will take a higher amount (i.e 33.76 g) of Na₂CO₃ than what was given (i.e 25.3 g) to react completely with 34.5 g of FeCl₃. Therefore, Na₂CO₃ is the limiting reactant and FeCl₃ is the excess reactant.
Why does solid water (ice) float when placed in liquid water? *
Ice does not float in liquid water.
Ice is less dense than liquid water.
Ice is more dense than liquid water.
The densities of liquid water and ice are the same .
Answer:
Ice is less dense than water.
What is POH?
A. pH = log[OH-]
B. POH =[ht][OH-]
C. pOH = -log(OH)
D. pH = -log[H+]
Answer:
The answer is C
Explanation:
2.2.2: The pH Scale
pOH = -log[OH-]
Explain the concept of “Happy Atoms” as it relates to why atoms bond together.
Answer:
I think this means that they always compatible so th er e basically friends and they stick together. c: hope I helped
Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. An industrial chemist studying this reaction fills a 200. mL flask with 3.9 atm of sulfur dioxide gas and 3.2 atm of oxygen gas, and when the mixture has come to equilibrium measures the partial pressure of sulfur trioxide gas to be 1.6 atm. Calculate the pressure equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. Round your answer to 2 significant digits.
Answer:
0.20
Explanation:
Step 1: Write the balanced equation
2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g)
Step 2: Make an ICE chart
2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g)
I 3.9 3.2 0
C -2x -x +2x
E 3.9-2x 3.2-x 2x
Step 3: Find the value of x
The partial pressure at equilbrium of SO₃ is 1.6 atm. Then,
2x = 1.6 atm
x = 0.80 atm
Step 4: Calculate the partial pressures at equilibrium
pSO₂ = 3.9-2(0.80) = 2.3 atm
pO₂ = 3.2-0.80 = 2.4 atm
pSO₃ = 1.6 atm
Step 5: Calculate the pressure equilibrium constant
Kp = pSO₃² / pSO₂² × pO₂
Kp = 1.6² / 2.3² × 2.4
Kp = 0.20
What are the products of the acid-base reaction of sodium carbonate with acetic acid?
Answer:
The mixture quickly foams up with carbon dioxide gas. If enough vinegar is used, all of the baking soda can be made to react and disappear into the vinegar solution. The reaction is: Sodium bicarbonate and acetic acid reacts to carbon dioxide, water and sodium acetate.
Explanation:
hope this helps
Which change happens during evaporation?
A. A gas turns into a liquid.
B. A liquid turns into a gas.
C. A solid turns into a liquid.
D. A liquid turns into a solid.
Answer:
B.) A Liquid turns into Gas.
What is the Scientific notation for 0.10050
Answer:
1.005 x [tex]10^{1}[/tex]
Explanation:
A chemist adds of a M calcium sulfate solution to a reaction flask. Calculate the mass in grams of calcium sulfate the chemist has added to the flask
Answer:
1.23 g
Explanation:
A chemist adds 1.55 L of a 0.00582 M calcium sulfate solution to a reaction flask. Calculate the mass in grams of calcium sulfate the chemist has added to the flask.
Step 1: Given data
Volume of the solution (V): 1.55 LMolar concentration of the solution (C): 0.00582 M (0.00582 mol/L)Step 2: Calculate the moles (n) of calcium sulfate added
We will use the following expression.
n = C × V
n = 0.00582 mol/L × 1.55 L
n = 0.00902 mol
Step 3: Calculate the mass corresponding to 0.00902 moles of calcium sulfate
The molar mass of calcium sulfate is 136.14 g/mol.
0.00902 mol × 136.14 g/mol = 1.23 g
If I use warm water on my plants then they will grow faster as hot water increases metabolism this is an example of
Answer:
The options are
A. a hypothesis
B. a theory
C. a research question
D. a scientific explanation
The answer is A. a hypothesis
Explanation:
A hypothesis is referred to as a brief explanation on the occurrence of an event.
In the example above using of warm water on plants was inferred to make it grow faster as hot water increases the metabolism.
Which describes a difference between cephalopods and gastropods?
Cephalopods have a water vascular system, and gastropods have an open circulatory system.
Cephalopods live only in ocean environments, and gastropods live in a variety of environments.
Cephalopods have a simple nervous system, and gastropods have a complex nervous system.
Cephalopods are the largest group of mollusks, and gastropods are the smallest group of mollusks. CAN SOMEONE PLZZZZ ANWER THIS I WILL GIVE U 15 PIONTS
Answer:
B
Explanation:
I took the test
Answer:
The correct answer is B
Explanation:
When NH3(aq) is added to Cu2 (aq), a precipitate initially forms. Its formula is:
a. Cu(NH)3
b. Cu(NO3)2
c. Cu(OH)2
d. Cu(NH3)22
e. CuO
When NH₃(aq) is added to Cu₂(aq), a precipitate initially forms. Its formula is Cu(NH₃)². The correct option is d.
What is a chemical formula?A chemical formula is a representation of chemical elements and chemical compounds. The chemical letters are used to write the chemical formula. The charges if present is written by charges symbols like plus, minus.
The chemical reaction is
NH₃(aq) + Cu₂(aq) = Cu(NH₃)²
This is called a chemical reaction, which contains reactant on the left side and products on the right side. The precipitate that is formed is copper ammonia whole twice.
Precipitation is the solid crystals' substance that is come out at the surface of the liquid. It is collected in solid form, and it is called a precipitate.
Thus, the correct option is d. Cu(NH₃)².
To learn more about chemical formulas, refer to the link:
https://brainly.com/question/15138610
#SPJ2