For problems 1-6, find the average atomic mass of the following mixtures of isotopes. Show your work for full credit. Iodine-127 (80%), Iodine-126 (17%), Iodine-128 (3%)
Answer:
126.86
Explanation:
Iodine-127 (80%)
Iodine-126 (17%)
Iodine-128 (3%)
For a mixture of isotopes, the average atomic mass is obtained by summing the multiplication of the atomic mass and percentage composition of the individual isotopes. This is given as;
Average Atomic Mass = ( 80 / 100 * 127) + (17 / 100 * 126) + (3 / 100 * 128)
Average Atomic Mass = 0.8 * 127 + 0.12 * 126 + 0.03 * 128
Average Atomic Mass = 101.6 + 21.42 + 3.84 = 126.86
How many valence electrons does this contain... 1s^2 2s^2 2p^4 HOw do you figure this out
Answer:
6
Explanation:
The electronic configuration of the atom is:
1s² 2s² 2p⁴
The valence electrons are the electrons in the outermost shell of an atom. The number electrons in the highest orbitals with the highest quantum number will determine the valency of the atom.
For the given atom:
2s² 2p⁴ is the orbital = 2 + 4 = 6
There are 6 valence electrons in the given atom
how do i get the area of a shape
i need the name of the substance showing the steps: N2H4
How many moles of O are in Calcium hydroxide - Ca(OH)2?
safety.
1. Drop a paper of A-4 size and a piece of wood/plastic about 2-3 inches long,
rom a height more than 10 feet. Note the time for both to hit the ground. Now repeat
he experiment by folding the paper once, twice, thrice... (as many time as you can).
Vhy every time the travel time reduces for paper and remains the same for
ooden/plastic piece. Does the paper at any stage hit ground before wooden/plastic
ece? If yes, then why?
(3 marks)
Answer:
because gravitational force effects on wood as compare to paper
give reason joule is a derived unit
Joule is a derived unit as, J = Nm, and N = kg m/s². So, joule depends upon many such physical units and hence, it is a derived unit.
More:-
Derived units: Units which are dependent on other physical units are known as derived units. Ex: acceleration (a), velocity (v). Fundamental units: Units which do not depend upon other units. Ex: cd (candela), kg (kilograms), etc.When water forms beads on a surface, as it does on the hood of a freshly waxed car, we can say that the water is ________ its contact with the surface because the cohesive forces are _______ than the adhesive forces.
Answer:
When water forms beads on a surface, as it does on the hood of a freshly waxed car, we can say that the water is minimizing its contact with the surface because the cohesive forces are larger than the adhesive forces
Explanation:
A waxed car's surface is covered wax which is an hydrocarbon having long chains that are very hydrophobic and therefore there is little interaction between the surface covered in wax and the cohesive forces in the water is much larger than the adhesive forces between the water and the freshly waxed car's surface which makes the water bead up to minimize the contact surface with the car's metal surface that results in limiting of the rust.
plsssssssssssssssssssssssssssss help
Answer:
a. compound; anion + anion
b. ionic; cation + anion
c. ionic; cation + anion
d. compund; anion + anion
Hi, please I need help
Calculate the mass of ethanol (alcohol) that theoretically can be made by fermenting 1.00kg of sugar. The equation is:
C₁₂H₂₂O₁₁(aq)+H₂O(I) = CH₃CH₂OH(aq)+CO₂(g)
sugar ethanol
The mass of ethanol (alcohol) = 538.016 g
Further explanationGiven
Reaction
C₁₂H₂₂O₁₁(aq)+H₂O(I) = CH₃CH₂OH(aq)+CO₂(g)
1 kg of sugar = 1000 g
Required
The mass of ethanol
Solution
Balanced equation
C₁₂H₂₂O₁₁(aq)+H₂O(I) = 4CH₃CH₂OH(aq)+4CO₂(g)
mol of sugar (MW = 12.12+22.1+11.16=342 g/mol) :
mol = mass : MW
mol = 1000 g : 342 g/mol
mol = 2.924
From the equation, mol ratio of C₁₂H₂₂O₁₁ : CH₃CH₂OH = 1 : 4, so mol ethanol =
= 4 x mol sugar
= 4 x 2.924
= 11.696
Mass of ethanol(MW=46 g/mol) :
mass = mol x MW
mass = 11.696 x 46
mass = 538.016 g
I thought heavy elements like iron & gold were dense & sank into the interior of the molten planet? How did gold get on top of the less dense crust?
Answer:
If it is denser then water it shall float but if water has a higher density the object sinks
Explanation:
Vivian went on a bicycle trip through Germany with her family. One afternoon, she rode her bicycle along a long flat road at a constant speed for 24 kilometers (km). The ride took her 1.2 hours (h). At what speed did she ride her bicycle?
A. 0.05 h/km
B. 20 mi/h
C. 20 km/h
D. 28.8 km•h
Answer:
d = distance traveled by her on her bicycle on a long flat road = 24 kilometer
t = time taken by her to travel distance "d" on her bicycle on a long flat road = 1.2 hours
v = average speed of vivian = ?
we know that average speed is given as
v = d/t
inserting the values in the above formula
v = 24 kilometer / 1.2 hour
v = 20 kilometer/hour
hence the correct choice is
C) 20 km/h
Why is it helpful to cross my organisms
A test cross can help determine whether a dominant phenotype is h.o.m.o.zygous or heterozygous for a specific allele.
hope this helps ^^
Using the model for the formation of Scandium Fluoride (an ionic compound), write the chemical formula.
Answer:
Sc3F3
I hope its help for you
HELPPP PLEASE TIME LIMITED!!!
Moving electrons are known as ______.
Answer:
Electricity
Moving electrons are known as electric current, also known as Electricity.
Please help. I’m really struggling. No wrong answers please, if you don’t know it please don’t answer, I’m already failing the class.
Answer:
[tex]C_{3}H_{3} O_{1}[/tex]
Explanation:
There are empirical formula calculators on the search engine that starts with G (This word is blocked by Brainly) and if you really need to use it, there's an option you can choose. However, I will try to explain this.
C = 65.4
H = 5.5
O = 29.1
We first need to divide the percentages by their molar mass.
65.4/12.01 = 5.44
5.5/1.008 = 5.46
29.1/16 = 1.8
We then need to divide these numbers by the smallest number we obtained.
1.8 is smaller than 5.46 and 5.46, so we would divide all three numbers with 1.8.
5.44/1.8 = 3
5.46/1.8 = 3
1.8/1.8 = 1
This means that there are 3 atoms of C and H and 1 atom of O, giving us the empirical formula of [tex]C_{3}H_{3} O_{1}[/tex].
Most of the energy that drives the water cycles comes from which of the following?
O The sun
O Earth's core
O Earth's oceans
O The equator
variable for momentum
Answer:
p is the variable for momentum formula is p=mv
Answer:
p
Explanation:
in this equation you insert the known values.. p=mb than you will et your answer
1. What atoms make up a molecule of acetic acid? *
O carbon, sodium, oxygen
sodium, hydrogen, carbon
carbon, hydrogen, oxgyen
sodium, hydrogen, oxgyen
Answer:
carbon,hydrogen and oxygen
molecular formula=CH3COOH
How many moles are there in 1.20x10^24 units of Platinum?
Answer:
#50316 in Other Chemistry for Meagan
How many moles of glucose does 1.2 x 1024 molecules represent? 1 mole of any substance has 6.02 x 1023 . For getting thenumber of moles we can divide 1.2 x 1024/6.02 x 1023 and we receive 2 moles.
To make a Br2 bond, how many total valence electrons are required?
1. 7
2. 14
3. 8
4. 16
Answer:
2. 14
Explanation:
To form Br₂ bond, a total of 14 electrons are needed.
Bromine is an element in the 7th group on the periodic table. It has 7 valence electrons.
In forming the bromine gas, the two atoms of bromine shares 7 electrons each. These electrons are from their outermost shell. The outermost shell is the valence shell. So, two atoms donating 7 electrons gives 14 electrons.What is the transfer of thermal energy due to direct contact?
Answer:
Conduction
Explanation: In conduction, heat is transferred by direct contact. The better the conductor, the more rapidly heat will be transferred.
How are science and technology related
There is no answer, science is about empirical knowledge, technology is the sum of techniques, skills, methods, and processes. I do not believe that you will find a answer for that.
The average size of a grocery store chicken has more than doubled in the past century. What is the most likely reason for this change?
Complete Question:
The average size of a grocery store chicken has more than doubled in the past century. What is the most likey reason for this change?
Group of answer choices.
A. Natural selection resulted in a larger species of chicken.
B. Artificial selection created a larger breed of chicken.
C. Mutations occur less frequently in chickens than they did a century ago.
D. Grocery stores used to sell younger chickens.
Answer:
B. Artificial selection created a larger breed of chicken.
Explanation:
The average size of a grocery store chicken has more than doubled in the past century. The most likely reason for this change is that artificial selection created a larger breed of chicken.
Artificial selection, also known as selective breeding can be defined as the process of identifying desirable traits in living organisms such as animals and plants, and selectively taking steps to ensure that those phenotypic traits are perpetuated in the offsprings or future generations.
This ultimately implies that, farmers or breeders are saddled with the responsibility of choosing which plant or animal are selected for the production of favorable (special) offsprings.
gold is one of the group Metals called the coinage metals. how many atoms of gold are in a u.s. eagle a gold alloy bullion coin with a mass of 31.1 g Au?
Answer:
9.51 x 10²² atoms Au
Explanation:(mass: 31.1g Au)
(m. mass: 196.967 g/mol Au)
(atoms: ?)
(31.1g Au x 1 mol Au x 6.022 x 10²³ atoms Au/ 196.967g Au x 1 mol Au)
answer this in your own words and I will mark brainlist
Answer:
hlo please help me to do my question
Answer:
hii i m here hope your day will energitic
Pls help I’m about to cry I cant do this it’s due in ten min
Answer:
C
Explanation:
When a dentist has you do xrays there are waves thats what the vest is for
In what situation can energy be created or destroyed?
1. in a nuclear reaction
2. during photosynthesis
3. never
4. when work is done
Which of the following is an example of a situation in which an egg is receiving thermal energy through convection?
A. The egg is kept warm by its mother in the nest
B. An egg cracked on a hot sidewalk starts to cook
C. The egg is hard boiled in a pot of water
D. A metal pan on the stove fries the egg