Which of these is a example of a physical change
1. An atom of an elephant has atomic mass of 39 and has number of neutrons as 20 calculate protons number.
2. An atom of an elephant has the atomic number of 13 and 14 neutrons
A. What is the mass number
B. write the nuclear notation given the atoms as X.
C. How many electrons does atom X have?
D. what is number of protons.
Answer:
See Explanation
Explanation:
1) Let us recall that;
Mass number = number of protons + number of neutrons
Where;
Number of protons = ?
Number of neutrons =20
Mass number =39
Number of protons = mass number - number of neutrons
Mass of protons =39 - 20= 19 protons
2) Atomic number = 13
Number of neutrons =14
Then the mass number =13 +14 =27
The symbol of the element is 27X13
The number of protons= the number of electrons =13
The atomic number is the same as the proton number =13
2NO(g) + 5H2(g) ⟶ 2NH3(g) + 2H2O(g)If 45.4 grams of NO and 12.1 grams of H2 react, what is the largest amount of ammonia that can be formed? The final answer should be reported to one place after the decimal point
Answer:
25.8g of NH3 can be formed
Explanation:
To solve this question we must convert the mass of each reactant to moles using molar mass. With the chemical equation we can find limiting reactant. The moles of limiting reactant are used yo find the moles of ammonia produced and its mass:
Moles NO -30.01g/mol-
45.4g * (1mol / 30.01g) = 1.51 moles
Moles H2 -Molar mass: 2.01g/mol-
12.1g * (1mol / 2.01g) = 6.02 moles
For a complete reaction of 6.02 moles of H2 are needed:
6.02mol H2 * (2mol NO / 5mol H2) = 2.41 moles NO are needed
As there are just 1.51 moles, NO is limiting reactant
Moles NH3:
1.51 moles NO * (2mol NH3 / 2mol NO) = 1.51 moles NH3
Mass NH3 -Molar mass: 17.031g/mol-
1.51 moles NH3 * (17.031g / mol) =
25.8g of NH3 can be formedA seais usually defined as A.A body of freshwater that is not connected to the ocean B. A body of freshwater that is connected to the ocean C. A body of salt water that is not connected to the ocean D. Body of salt water that is connected to the ocean
Answer:
D. Body of salt water that is connected to the ocean
Explanation:
An ocean is a body of salt water which covers approximately 70% of the Earth's surface. About 97% of the Earth's water is comprised of ocean and as such it is the most prominent and defined feature of the Earth. There are basically four (4) categories of an oceanic basin and these are;
1. The Pacific ocean.
2. The Artic ocean.
3. The Atlantic ocean.
4. The Indian ocean.
A sea is usually defined as a body of salt water that is connected to the ocean and are surrounded (enclosed) by land partially.
Basically, a sea is formed where a land and an ocean meet and as a result, an ocean is usually bigger than a sea.
Some examples of seas around the world are Red sea, Mediterranean sea, Sargasso sea, Caribbean sea, Baltic sea, Caspian sea, Chuckchi sea, etc.
Answer:
Yes The Anwer is D Hope This Help:)
7. What is the missing part of this fusion equation?
What is the missing part of this fusion equation?
2 1H+? → 3 2He + 1 0 n
Select the correct answer. Use the periodic table to help you.
1) 3 1 н
2)3 2 Не
3) 2 1 0n
4)2 1 H
Answer:
2 1 H
Explanation:
We must remember that a nuclear equation is only said to be balanced when the mass and charges on both sides of the nuclear reaction equation correspond.
If we look at the nuclear equation; the total mass on the right hand side is 4 units while the total charge on the right hand side is two units.
This implies that the missing particle must be 2 1 H
where is distillation used
Answer:
During separation of substances with different boiling points, fractional distillation is used.
During separation of substances in an eutectic mixture or azeotropic mixture, steam distillation is used.
A d orbital can
hold ____ electrons.
A. 2
B. 6
C. 10
D. 14
Answer:
10 electrons
Explanation:
Reptiles, amphibians, and fish are all cold-blooded animals. Their body temperatures are determined by their surroundings. How does a cold-blooded animal’s ability to digest food change in colder temperatures?
Si se sabe que el bronce se forma con 60% de cobre y 40% de estaño¿cual sera la masa de cobre contenida en 200 gramos de bronce
Answer:
Mass of copper in 200 g bronze is 120 g.
Explanation:
If it is known that bronze is formed with 60% copper and 40% tin, what will be the mass of copper contained in 200 grams of bronze?
Percentage of copper in bronze = 60 %
Percentage of tin in bronze = 40 %
Mass of bronze = 200 grams
Mass of copper in bronze = 60 % of 200 g
= 0.6 x 200 = 120 grams
Mass of copper in 200 g bronze is 120 g.
In a titration of hydrobromic acid (HBr) against sodium hydroxide (NaOH), 22.20 mL of 0.150 M NaOH is required to neutralize 36.60 mL of HBr. Calculate the molarity of the HBr. M1V1=M2V2
Answer:
[HBr] = 0.0910 M
Explanation:
NaOH → Strong base
HBr → Strong acid.
This is a titration that involves a strong acid and a strong base, so the recaction is about acid base equilibrium.
Formula for titration in the equivalence point is:
mmoles of acid = mmoles of base
M . Volume of acid = M . volume of base
We replace data:
M . 36.60 mL = 0.150 M . 22.20 mL
M = (0.150 M . 22.20 mL) / 36.60 mL
M = 0.0910 mol/L
Which cell part is responsible for energy release?
A. nucleus
B. ribosome
C. mitochondrion
D. Golgi apparatus E. endoplasmic reticulum
Answer:
mitochondria is responsible for energy
Which represents the correst equilibrium constant expression for Cu(s) +2Ag<------> Cu^2 (aq) +2Ag(s)
Answer:
[tex]Kc=\frac{(Cu2)(Ag)^2}{(cu)(Ag)^2}[/tex]
Explanation:
because it is products / reactants
Hope this helps:)
Why do food scientists need to understand chemistry?
A.They study how to make plants produce certain chemicals
B.They use complicated machines to produce food products
C.They use chemicals as flavorings and preservatives
D.They study the effects of different foods on the body
Answer:
I think it is A
Explanation:
A.They study how to make plants produce certain chemicals
Fe2O3(s) + 3H2(g) → 2Fe(s) + 3H2O(1)
How many moles of iron can be made from 3 moles of Fe2O3?
ANSWER - 6 MOLES OF IRON
Fe2O3(s) + 3H2(g) → 2Fe(s) + 3H2O(1)
One moles of Fe2O3 forming 2 moles of Fe
3 moles of Fe2O3 will form 2×3 = 6 moles of iron
What mass of methanol (CH3OH) is produced when 140.1 g of carbon
monoxide reacts with 12.12 g of hydrogen?
CO(g) + 2H2(g) → CH2OH()
A. 160.2g
B. 96.12 g
C. 6.06 g
D. 192.2g
Answer:
B. 96.12 g
Explanation:
To solve this question we must convert each reactant to moles. Using the balanced equation we can find limiting reactant. With moles of limiting reactant we can find the moles of methanol and its mass:
Moles CO -Molar mass: 28.01g/mol-
140.1g CO * (1mol / 28.01g) = 5.0 moles CO
Moles H2 -Molar mass: 2.01g/mol-
12.12g * (1mol / 2.01g) = 6.03 moles H2
For a complete reaction of 5.0 moles of CO are required:
5.0moles CO * (2mol H2 / 1mol CO) = 10.0 moles of H2 are required
As there are just 6.03 moles, H2 is limiting reactant.
The moles of methanol produced are:
6.03 moles H2 * (1mol CH3OH / 2mol H2) = 3.015 moles CH2OH
Mass CH3OH -Molar mass32.04g/mol-:
3.015 moles CH2OH * (32.04g/mol) =
96.6g CH3OH ≈ B. 96.12 g
which environment would experience more humidity
A: Desert
B: Grassland
C: Mountain
D: Swamp
Answer:
Explanation:
You'r answer should be D
2.00 liters of gas at 1.00 atm and conpresssed it to a pressure of 6.00 atm, what would the volume of the gas be
Answer:
[tex]V_2=0.5L[/tex]
Explanation:
From the question we are told that:
initial Volume [tex]V_1=2.00L[/tex]
initial Pressure [tex]P_1=1 atm[/tex]
Final Pressure [tex]P_2=6atm[/tex]
Generally the equation for Final Volume V_2 is mathematically given by
Since Boyle's law states
[tex]P_1V_1=P_2V_2[/tex]
[tex]V_2=\frac{P_1V_1}{P_2}[/tex]
[tex]V_2=\frac{2*1}{6}[/tex]
[tex]V_2=0.5L[/tex]
Tides are caused by the pull of gravity by the _____ and the _____.
(fill in the blanks)
tides are caused by the gravitational force of the sun and the moon
What is the energy transformation from wind to usable energy
Answer:
A turbine takes the kinetic energy of a moving fluid, air in this case, and converts it to a rotary motion.
Explanation:
calculate the volume occupied by 15 moles of a gas at 1.14 atm and 265K. A-286.3L B-321.6L C-247.4L D-304.5L
Answer:
A- 286.3L
Explanation:
Using the ideal gas law equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K)
According to the information given in this question;
P = 1.14atm
V = ?
n = 15moles
T = 265K
Using PV = nRT
V = nRT ÷ P
V = (15 × 0.0821 × 265) ÷ (1.14)
V = 326.35 ÷ 1.14
V = 286.27 L
V = 286.3L
What does it mean if an element has 8 valence electrons?
Answer:
the answer is the D, it has a full octet
If Beryllium were to lose a proton, it would become a(n)
Answer:
an anion
Explanation:
since it lost a proton..it now has 3 protons and four electrons and possesses a minus charge since it is no longer neutrally charged..this minus charge makes it an anion
True or False. The loads in a parallel circuit do not necessarily all have the same amount of current in them.
Answer:
TRUE
Explanation:
[tex]what \: is \: sound \: \: {?} [/tex]
Answer:
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain.
Explanation:
this is what i found hope it helps :)
Answer:
Sound is a form of energy which is caused due to the vibration of an object.
How many grams of AlCl3 are needed to completely react with 2.25 of NaOH?
Explanation:
hope the picture above help u understand I did it in step so it would be easier to understand:)
HELP FAST PLS !!!!!!!!!!!!!!!!
Answer:
The Peruvian area of the jungle, living in the high trees is the monkey's habitat.
(I'm not fully sure what a niche is) but:
Feeding on hazelnuts and scavenging for food along the jungle floor is the monkey's niche.
Explanation:
I really hope I was able to help!
Good luck and have a great day :)
gases have maximum density and rigidity true or false
Answer:
This statement is true.........
Answer:
i think true
Explanation:
Can you please help me with this?
What happens with the evaporation of raindrops in the atmosphere?
Answer:
they become water vapor and after that, they become a type of precipitation
What are changed after fushing the cover of the jar?
Answer:
the volume decreases and the pressure increases.
Answer:
When you first set the water balloon on top of the jar, the air pressure outside the jar and the air pressure inside the jar are the same. ... So now there is less air, less stuff, in the jar
what is an equationwhat is a what is a catalyst