Một chất phóng xạ có chu kỳ bán huỷ là 10 năm, Hỏi bao nhiêu năm thì lượng phóng xạcòn 10%. Cho biết phản ứng phân hủy chất phóng xạ là phản ứng bậc
Answer:
what
Explanation:
0
10
o
20
30
40
90
60
80
50
g
70
0
1
2
3
4
6
9
7
8
5
g
.1
.2
.3
.4
.6
.7
.8
.9
.5
9
Can this balance be read to the nearest milligram?
O no
O yes
Answer:
30
Explanation:
yes of courseeee i cant balance with the nearest milligram
What would happen if there were no gravity anywhere in the universe?
Objects would no longer be drawn toward each other, because there would be no sloping surface for them to fall down. Instead, they would fly off in whatever direction gravity was keeping them from going.
Answer:
All items in the universe, humans, objects, and the planets, would be floating around. Everything would become weightless.
Which circle contains the mixture? Is it D?
What is wrong with this model of the atom.
Answer:
A. The neutrons and electrons are in the wrong place.
Explanation:
The atom's nucleus contains both protons and neutrons, whilst the electrons are arranged in shells around the nucleus.
draw the lewis dot structure of C4H8N2O3
Explanation:
Refer to the attachment
Extrashots:-
C4H8N2O3 is called asparagine .
What are the substances you start with in a chemical reaction called?
A. The intermediates
B. The products
C. The mixture
D. The reactants
Which location in the diagram above is the Northern Hemisphere experiencing summer?
Location A
Location B
Location C
Location D
Answer:
c
Explanation:
Answer:
Location b is experiencing summer
In the Northern Hemisphere, Summer season is represented here location B.
Magnesium reacts with a certain element to form a compound with the general formula MgX. What would the most likely formula be for the compound formed between Lithium and element X?
Answer:K2X
Explanation: Valency can be defined as the combining power of an element. It is the valency that dictates the value an element will have when writing a chemical formula for its compound.
MgX is a compound of magnesium and an element X. The valency of magnesium in most of its compound is +2. Now for the 2 to have been absent in the chemical formula, this shows that the element X itself have a valency if -2 for the valencies of both to have canceled out.
Now considering the element potassium, it is an alkaline metal belonging to group 1 of the periodic table. Hence, it is expected that it has a valency of +1
Forming a compound with element X means there would be an exchange of valencies between the two. We have established that x has a valency of -2. The formula of the compound thus formed by exchanging the valencies of both element would be K2X
The chemical formula for the compound formed between Lithium and element X is Li₂X.
What is valency?Valency can be described as the combining power of a chemical element. It is the valency that describes the value an element will have in the chemical formula for that compound.
MgX compound is a compound of magnesium and an element X. The valency of magnesium is +2. The chemical formula shows that the element X itself has a valency of -2 which gave a neutral compound.
Now given element is Lithium, it is an alkali metal of group 1 of the periodic table. It has a valency of +1 as it has one electron in its valence shell.
Forming a compound with element X, there will be an exchange of valencies between the two. As element X has a valency of -2. The formula of the formed compound by exchanging the valencies of Lithium and element X would be Li₂X
Learn more about Valency, here:
https://brainly.com/question/12744547
#SPJ6
what is the percent by volume of a solution formed by mixing 25ml of isopropanol with 45ml water
Answer:
I assume that you mix the 25 mL alcohol with 45 mL water.
The answer depends on a big IF : IF the volumes are additive. Very often volumes of liquids are not additive
Total volume = 70 mL
isopropyl alcohol %(v/v) = 25mL/ 70 mL * 100 % = 35.7% v/v
The answer should have only 2 significant digits: 36%v/v
Explanation:
Hope it helps
The percent by volume of a solution formed by mixing 25 ml of isopropanol with 45 ml of water is 35.71% which is rounded off to 36%.
What is meant by percent by volume of a solution?Percent volume is defined as the concentration of a particular solute which is measured in terms of volume present in a solution. The volume of the solution is present in the denominator which indicates the total volume of all components .
It is expressed as,
percent volume= volume of solute/volume of solution×100
It is used for solutions which are made by mixing two components . It is one of the ways of expressing concentrations of mixture with a dimensionless quantity.
Percent volume of the given solution is calculated by substituting the given values in the formula like, 25/70×100=35.71%
Thus, the percent by volume concentration of the solution is 35.71%≈36%.
Learn more about percent by volume ,here:
https://brainly.com/question/14710169
#SPJ2
detailed description of how group 1 atoms bond with group 7 atoms
Answer:
group 7 atoms react
Explanation:
When a group 7 element takes part in a reaction, its atoms each gain one electron. These atoms form negatively charged ions . The ions have a stable arrangement of electrons, with a complete outer shell.
does exercise increase, decrease or have no effect on the amount of carbon dioxide you exhale
Answer:
It increases the amount you exhale
Explanation:
The more you exercise and make your body work, the more oxygen you inhale which causes you to let out more carbon dioxide than if you were just resting.
where does fertilization occurs in human beings
In human beings fertilization occurs in fallopian tube
Answer:
Fertilization usually takes place in a fallopian tube that links an ovary to the uterus. If the fertilized egg successfully travels down the fallopian tube and implants in the uterus, an embryo starts growing.
Describe the structure and bonding in aluminium metal.
Answer: Metallic bonding.
Explanation: Aluminum forms metallic bonds with itself. This results in a metallic lattice structure.
Aluminum is found in the 13 group of periodic table and it mostly forms ionic bonds with metal. The structure of Aluminum is Orthorhombic mainly.
What is element?
Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same. Two or more than two atoms with different physical or chemical properties can not combine together to form an element.
The structure of Aluminum is Orthorhombic and it contains high neutron capture cross section. It is very stable in dry air but oxidizes in moist air. It reacts with oxygen to form Al₂O₃.Valence of Aluminum is III. Its electronic configuration is [Ar]3d¹⁰ 4s² 4p¹
Thus structure of Aluminum is Orthorhombic and metallic bond is formed by Aluminum
To know more about element, here:
https://brainly.com/question/8460633
#SPJ2
Select reason(s) why 1-hydroxy-2-methyl-5-isopropylbenzene is an incorrect systematic name for carvacrol.
a. If named with benzene as the parent, the methyl group needs to have the first locant in order to minimize the number of the third locant.
b. The substituents are not listed alphabetically.
c. If named with benzene as the parent, the hydroxyl group needs to have the first locant in order to minimize the number of the third locant.
d. The substituents are not listed in order of increasing mass.
The reason why 1-hydroxy-2-methyl-5-isopropylbenzene is not the correct systematic name for carvacrol is because the substituents are not listed alphabetically.
IUPAC nomenclature provides the correct and acceptable system of naming organic compounds which are internationally acceptable among scientists.
According to the rules of IUPAC nomenclature, compounds are named in alphabetical order. The names of the locants are ordered in such a way that they have the lowest number. Following IUPAC nomenclature, the correct name of the compound ought to be, 1-hydroxy-5-isopropyl-2-methylbenzene.
Learn more: https://brainly.com/question/11587934
What are the two parts of the third Step?
O Plug and solve
O Formula and solve
O Show work and solve
O Question and show work
Answer:
A
Explanation:
Answer:
I'm not quite sure what the question is. What is the third step? I think I can help, would you mind commenting what the third step is? :)
Explanation:
What did you include in your response? Check all that
apply.
o Organisms eat food to obtain carbohydrates, lipids,
and proteins, which are found in food.
Organisms use these molecules for energy and
growth.
Answer:
WHAT DID YOU INCLUDE IN YOUR RESPONSE
How many grams of potassium (K) contain 5.11 x 10^22 atoms of potassium?
The atomic mass of K is 39
from Avogadro's law
39g of K contains 6.02x10^23 atoms
therefore if
39=6.02x19^23
X=5.11×10^22
making X the subject of the formula
X= (5.11×10^22×39)÷6.02×10^23
X= 33g
The statement, that describes grams of potassium (K) contain 5.11 × [tex]10^{22}[/tex] atoms is "33.1 g."
What is an atom?An atom is a fundamental particle of matter that contains at least one proton.
1 mole will be of 6.022 × [tex]10^{23}[/tex] atoms
Then,
[tex]= 5.11*10^{22} \;atoms\;.\;\frac{1\;mol}{6.022*10^{23} \;atoms} \;.\;39.098\;g/mol\\\\= 33.171\;g[/tex]
≈ 33.1 g
As a result, 33.1 g of K contains 5.11 × [tex]10^{22}[/tex] atoms.
Hence, the correct option is 33.1 g.
Learn more about atoms here
https://brainly.com/question/19922822.
#SPJ2
What is the molarity of 98.0 g of phosphoric acid, H3PO4 in 1.00 L of solution. Please show your work.
Answer:
1.0001 M
Explanation:
Molarity = Mass/(Volume x molar mass)
Molarity = 98.0 g/(1.00 L x 97.994 g/mol)
Molarity = 1.0001 M
the molarity of 98.0 g of phosphoric acid, H3PO4 in 1.00 L of solution is 1.0001 M
what is the difference between molarity and molality ?Molarity can be defined as the number of moles of solute available in a definite concentration and amount of the solution, other wise called as moles per liters of a solution.
Molality of a solution can be defined as the number of moles per solute can be present in a kilogram of the solvent, which is moles per kilogram of a solvent.
Though the terms Molarity and Molality are quite similar but the sharp difference between them as it creates a huge difference while using this two form of calculation for various calculations.
Molarity = Mass/(Volume x molar mass)
Here, Molarity = 98.0 g/(1.00 L x 97.994 g/mol)
Molarity = 1.0001 M
learn more on molarity, here:
https://brainly.com/question/16727614
#SPJ2
HELP PLEASEEEEEEEEEEEEEEEEEEE
Answer:
1-air
2-decrease
3-water
4-gas
5-liquid
I THINK the answer to part b is A but I am not entirely sure
Explanation:
state what method you would use the separate water from a potassium iodide solution
Answer:
You can separate the Iodine from the water and convert the potassium iodide into elemental Iodine by mixing 1 part of a 5–13% solution of Iodine/Potassium Iodide with 1 part distilled water and 1 part 3% Hydrogen Peroxide Solution followed by 1/12 part 32.45% hydrochloric (Muriatic) acid.
Using the provided table and the equation below, determine the heat of formation (in kJ/mol) for CuBr₂.
CuCl₂ (s) + Br₂(l) → CuBr₂ (s) + Cl₂ (g) ∆H° = 64.1 kJ/mol
CuCl2= -205.9 kJ/mol
Br2= 0 kJ/mol
Cl2= 0 kJ/mol
The heat of formation of CuBr₂ (s) = -141.8 kJ/mol
The heat of reaction ΔH = ∑ΔHproducts - ∑ΔHreactants
ΔH = ΔHCuBr₂ (s) + ΔHCl₂ (g) - [ΔHCuCl₂ (s) + ΔHBr₂(l)]
where ΔHCuBr₂ (s) = heat of formation of CuBr₂ (s), ΔHCl₂ (g) = heat of formation of Cl₂ (g) = 0 kJ/mol, ΔHCuCl₂ (s) = heat of formation of CuCl₂ (s) = -205.9 kJ/mol, ΔHBr₂(l) = heat of formation of Br₂(l) = 0 kJ/mol and ΔH = heat of reaction = 64.1 kJ/mol
Substituting the values of the variables into the equation, we have
ΔH = ΔHCuBr₂ (s) + ΔHCl₂ (g) - [ΔHCuCl₂ (s) + ΔHBr₂(l)]
64.1 kJ/mol = ΔHCuBr₂ (s) + 0 kJ/mol - [-205.9 kJ/mol + 0 kJ/mol]
64.1 kJ/mol = ΔHCuBr₂ (s) + 0 kJ/mol + 205.9 kJ/mol - 0 kJ/mol
64.1 kJ/mol = ΔHCuBr₂ (s) + 205.9 kJ/mol
ΔHCuBr₂ (s) = 64.1 kJ/mol - 205.9 kJ/mol
ΔHCuBr₂ (s) = -141.8 kJ/mol
So, the heat of formation of CuBr₂ (s) = -141.8 kJ/mol
Learn more about heat of formation here:
https://brainly.com/question/13925548
1. Oxygen was discovered by Joseph Priestley in 1774 when he heated mercury (II) oxide, HgO, to decompose it to form its constituent elements. How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?
Given:
Unknown:
Mole ratio:
Solution:
2. In a blast furnace, iron (III) oxide is used to produce iron by the following (unbalanced) reaction:
Fe2O3(s) + CO(g) Fe(s) + CO2(g)
If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
Given:
Unknown:
Mole ratio:
Solution:
Final answer:
ugh pls help:(
Answer:
1. 7.81 moles HgO
2. n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.
Explanation:
How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?
2HgO ==> 2Hg + O2
125 g O2 x 1 mol O2/32 g x 2 mol HgO / mol O2 = 7.81 moles HgO
------------------------------------------------------------------------------------------------------------
If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
The no. of moles of CO are needed = 75.15 mol.
Fe₂O₃ + 3CO → 2Fe + 3CO₂,
It is clear that 1 mol of Fe₂O₃ reacts with 3 mol of CO to produce 2 mol of Fe and 3 mol of CO₂.
If 4.00 kg Fe₂O₃ are available to react, how many moles of CO are needed?
We need to calculate the no. of moles of 4.00 kg Fe₂O₃:
n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.
Using cross multiplication:
1 mol of Fe₂O₃ need → 3 mol of CO to react completely, from stichiometry.
25.05 mol of Fe₂O₃ need → ??? mol of CO to react completely.
The no. of moles of CO are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.
According to stoichiometry of the chemical equation, if 4000 g of iron oxide is available to react,25.04 moles of CO are needed.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
159.69 g iron oxide gives 28 g CO thus 4000 g iron oxide will give 4000×28/159.69=701.35 g which is 701.35/28=25.04 moles.
Learn more about chemical equation,here:
https://brainly.com/question/28294176
#SPJ2
Which of the following is based on facts and/ or evidence?
What is the density of a gas with a volume of 5.6 FL oz. and a mass of 37 grams?
Answer:
6.60
Explanation:
3nahco3(aq) + h3c3h5
What is the overall charge of an atom? Explain why
Answer:
atoms have no overall charge. this is because they contain equal numbers of positive protons and negative electrons
Materials Visible Uniform Not Visible Non- Uniform State of Matter 1. Sugar and water 2. Oil and water 3. Vinegar and water 4. Salt and pepper 5. leaf and water
Answer:
1. Uniform, non visible
2. Visible, non uniform
3. Uniform, non visible
4. Visible, non uniform
5. Visible, non uniform
Explanation:
A heterogeneous mixture is simply any mixture that is not uniform in composition — it's a non-uniform mixture of smaller constituent parts. By contrast, a mixture that is uniform in composition is a homogenous mixture
visible state of matter is when you can easily difference two components of a mixture
non visible is when the state of the matter in the substance is not visible to the eye, it can't be differentiated
Question 5 of 5
The rows in the periodic table are called periods. What is true about elements
in the same period?
O A. They have the same atomic mass.
B. Their atomic numbers increase by 1 from left to right.
C. Their magnetism increases in strength from left to right.
D. They have similar chemical properties.
SUBMIT
Answer:
B. Their atomic numbers increase by 1 from left to right
5._____is and example of an element and __is an example of compound
A. MIXTURES
B. CARBON
C. PURE
D. CARBON DIOXIDE
PLS ANSWER IT
ITS SCIENCE
Answer:
Carbon Dioxide is and example of an element and Carbon is an example of compound