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
salt water
pure substance
element
homogeneous mixture
heterogeneous mixture
compound
solution
Answer:
salt water heterogeneous mixture , pure substance compound,element solut8on
97
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Where is located the element with the electron
configuration [Kr] 5s? in the periodic table?
Pop se7419 Ford
19725 74
B - In period 5 and group 10
C - In period 4 and group 10
D - In period 5 and group 12
Calculate the current needed to provide 30000C of electricity In 5 minute
All of the following statements are true except:
Schist is an example of metamorphic rock.
Metamorphic rocks are formed under heat and pressure.
All metamorphic rocks come from parental rocks.
Metamorphic rocks can also be formed in ocean floors.
Answer:
Metamorphic rocks can also be formed in ocean floors.
Explanation:
The ocean floor is made up predominantly of basalts and are derived by the cooling an solidification of magma in this environment.
The ocean floor is made up primarily of igneous rocks and some sediments that have been deposited from the surface. Also, materials from deep within the subsurface can reach the ocean floor where they cool and solidify to form igneous rocks. Schists are examples of metamorphic rocks as well as gneiss.Answer: a is incorct
Explanation:
Categorize the following reaction: C3H8 + O2 ---> CO2 + H2O *
Synthesis Reaction
Combustion Reaction
Replacement Reaction
Decomposition Reaction
Answer:
it is a replacement reaction
4. The representative particle for an ionic compound is a
Answer:
unit formula??
Explanation:
pls help
Gold has a specific heat of 0.129 J/(g . C°). How much energy does a 0.700 gram piece of gold give off as it's temperature cools from 53.0°C to 22.0°C?
Answer:
2.8J
Explanation:
Given parameters:
Specific heat capacity = 0.129J/g°C
Mass = 0.7g
Initial temperature = 53°C
Final temperature = 22°C
Unknown:
Quantity of heat released = ?
Solution:
To solve this problem, we use the expression below;
H = m c Ф
H is the quantity of heat released
m is the mass
c is the specific heat capacity
Ф is the change in temperature
Now,
Insert the given parameters and solve;
H = 0.7 x 0.129 x (22 - 53) = -2.8J
The amount of heat released is 2.8J, the negative depicts the heat released.
Which is a property of all atoms?
a. More electrons than protons
b. A nucleus with a positive charge
c. A positively charged electron cloud
d. Same number of protons as neutrons
Give reasons
has valency
Magnesium
two
a
Answer:
Magnesium has valency equal to 2 +
Explanation:
because the electronic configuration of Mg is [2,8,2]. The nearest noble gas to magnesium is neon with electronic configuration of [2,8], to achieve this stable electronic configuration Mg can lose 2 valence electrons, hence its valency is 2 + .
Which type of wave is shown in the image?
The type of wave is shown in the image is transverse wave and the correct option is option B.
What are Transverse waves?A transverse wave is a wave in which particles of the medium vibrate at right angles, or perpendicular, to the direction that the wave travels.
Transverse waves commonly occur in elastic solids, oscillations, in this case, are the displacement of solid particles from their relaxed position, in the direction perpendicular to the propagation of the wave.
Transverse waves can travel through empty space as electromagnetic waves or be mechanical waves.
Therefore, The type of wave is shown in the image is transverse wave and the correct option is option B.
Learn more about Transverse waves, here:
https://brainly.com/question/13863548
#SPJ2
What are the two energy of the electrons outside the nucleus
Answer:
Unlike protons and neutrons, which are located inside the nucleus at the center of the atom, electrons are found outside the nucleus. Because opposite electric charges attract each other, negative electrons are attracted to the positive nucleus
7. Which of the following is NOT a characteristic that helps define syhthetic materials?
A) made from natural resources
B) underwent a chemical reaction
C) made to fit a specific function
D) made using metal
Answer:
made to fit a specific function
Calculate the number grams present in each sample below.
15 moles NO2
Answer:
Ok 15 miles NO2 you need the salt and pepper trick so mix it add water sit in it when you get cold write down uh temperature then you need to get out or it may kill you when it starts to get cold then go to the y- axis then you need to ask your teacher for help after you do the y-axis
Which of the following questions can be answered by science?
a. Are mind, body, and soul related to one another?
b. Are physical and chemical changes a part of nature?
с. Does studying science have better prospects than studying history?
d. Does philosophy provide a link between science and religion?
A balanced chemical equation is a direct presentation of the ___________.
law of conservation of momentum
law of conservation of energy
law of conservation of mass
ideal gas law
The law of conservation of mass is directly represented in a balanced chemical equation.
What is the law of conservation of mass?In chemistry, the law of conservation of mass says that in a closed or isolated system, matter cannot be created or destroyed in a chemical reaction.
For example: If we burn wood, the mass of ashes and gases is equal to the mass of wood before burning.
Thus, the Law of conservation of mass represent a balanced chemical equation.
Learn more about, law of conservation of mass, here:
https://brainly.com/question/13383562
A 4.50 g sample is analyzed and found to contain 3.22 g of carbon, 0.300 g of hydrogen, 0.221 g of nitrogen, and the rest is oxygen. The molar mass of the actual compound is found to be 285 g/mol. Find the empirical formula and then the molecular formula.
The empirical formula and the molecular formula are the same : C₁₇H₁₉NO₃
Further explanationGiven
3.22 g of carbon, 0.300 g of hydrogen, 0.221 g of nitrogen, and the rest is oxygen.
Required
The empirical formula and then the molecular formula.
Solution
Mass of Oxygen = 4.5 - (3.22+0.3+0.221)=0.759 g
Mol ratio of elements C : H : N : O =
3.22/12 : 0.3/1 : 0.221/14 : 0.759/16 = 0.268 : 0.3 : 0.016 : 0.047
Divide by 0.016 :
16.75 : 18.75 : 1 : 2.9375 = 17 : 19 : 1 : 3
(C₁₇H₁₉NO₃)n = 285
(12.17+19+14+3.16)n = 285
(285)n = 285
n = 1
Then the empirical formula and the molecular formula are the same
What happens to electrons during covalent bonding?
A. They are given up by atoms.
O B. They are shared between atoms.
C. They are transferred between atoms.
OD. They are taken in by atoms.
How do you write the formula for a compound made from Fe 3+ and OH -1 ions?
a: FeOH
b: Fe3OH
c: FeOH3
d: Fe (OH)3
What kind of reaction is this?
1. Synthesis
2. Decomposition
3. Single Replacement
4. Combustion
5. Double replacement
6. Acid-Base
Name the type of food additive that stops the food reacting with oxygen.
Answer:
Antioxidants such as vitamin C are preservatives by inhibiting the degradation of food by oxygen. Bulking agents such as starch are additives that increase the bulk of a food without affecting its taste.
if input energyis 100J and useful is 70J what is the waste energy
Answer:
waste energy = 30 J
Explanation:
Given that.
Input energy = 100 J
Useful energy = 70 J
We need to find the amount of waste energy.
Waste energy = total energy - used energy
= 100 J - 70 J
= 30 J
Hence, 30 J of energy is waste energy.
How many moles of Cu2S can be formed from 11 moles of HCl?
Answer:
hi
Explanation:
hi
I need to know what is Mitosis ♀️
Answer:
a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
Explanation:
A box is 1 m high, 2.5 m long, and 1.5 m wide, its volume is 5 mº.
true or false
Answer:
false
Explanation:
Because volume is in m3
Answer:
False
Correct answer: 3.75m³
Explanation:
Given parameters:
Height of box = 1m
Length of box = 2.5m
Width of box = 1.5m
Unknown:
Volume of the box = ?
Solution:
The volume of the box is given as:
Volume = length x height x width
Volume = 2.5 x 1 x 1.5
Volume = 3.75m³
How does energy change matter?
Answer:
Adding or removing energy from matter causes a physical change as matter moves from one state to another. For example, adding thermal energy (heat) to liquid water causes it to become steam or vapor (a gas). And removing energy from liquid water causes it to become ice (a solid).
Explanation:
Your welcome
In the reaction below, how would adding more of product C affect the equilibrium of the
system?
A + B 2 C + D (2 points)
VE
Shift it to the right toward the products.
M
Shift it to the left toward the reactants.
Pr
Equally create more products and reactants.
Da
Ро
It would have no effect.
Answer:
Shift it to the left toward the reactants
Explanation:
The direction of movement of a reaction at equilibrium has been explained by a man called HENRY LOUIS in his principle. According to this principle, a reaction will shift in response to a stress on equilibrium. The stress can either be effects of temperature, pressure, concentration etc on the reaction equilibrium.
- An addition of a reactant or product will cause the reaction to shift towards the opposite direction of the substance added. For example, in this question, the following reaction was given:
A + B ----> C + D
C is a product, meaning that if more of product C were added to this reaction, the reaction will shift towards the left (reactant side) because there are now more products. In other words, the reactants will be favored if there is an increase in the concentration of the products.
explain why the sun will not explode at any point in its life cycle
Answer:
i no now dethankyou
Explanation:
how to find gram molecular mass
Answer:looks for it
Explanation:
8. An element that has strong intermolecular forces is most likely to have:
•a boiling point below room temperature
•a melting point below room temperature
•a boiling point very close to its melting point
•a very high melting point
Answer:
a very high melting point answer
How many moles would be equal to 22.4 g of CO2?
Answer:
Number of moles = 0.51 mol
Explanation:
Given data:
Mass of CO₂ = 22.4 g
Number of moles = ?
Solution:
Number of moles of CO₂:
Number of moles = mass/molar mass
Molar mass of CO₂ = 44 g/mol
by putting values,
Number of moles = 22.4 g/ 44 g/mol
Number of moles = 0.51 mol