Answer:
Hydrogen
Lithium Beryllium Fluorine
Sodium Magnesium Chlorine
Potassium Calcium Bromine
Rubidium Strontium Iodine
Explanation:
and much more i had a project about this stuff
Elements on the same period will appear on the same row in the periodic table.
The periodic table is arranged in groups and periods. The vertical columns are the groups while the horizontal rows are the periods. Elements in the same group are chemically similar while elements in the same period have the same number of shells.
The question is incomplete because the letters are not shown. However, elements on the same period will appear on the same row in the periodic table.
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When [H+] = 4.0 × 10–9 M in water at 25°C, then
Kw =1.0×10–14.
b. pOH = 7.
c. [H3O+] = [OH–].
d. pH= 7
e. A-D are all correct
Answer:
a. Kw = 1.0 × 10⁻¹⁴
Explanation:
a. Let's consider the self-ionization of water.
2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻
The ion-product of water (Kw) at 25 °C is:
Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴
c. Considering [H⁺] = [H₃O⁺] = 4.0 × 10⁻⁹ M, the concentration of OH⁻ is:
[OH⁻] = 1.0 × 10⁻¹⁴/[H₃O⁺] = 2.5 × 10⁻⁶ M
b. We can calculate the pOH using the following expression.
pOH = -log [OH⁻] = -log 2.5 × 10⁻⁶ = 5.6
d. We can calculate the pH using the following expression.
pH = -log [H⁺] = -log 4.0 × 10⁻⁹ = 8.4
When [H+] = 4.0 × 10–9 M in water at 25°C, then the [tex]Kw =1.0\times 10^-^1^4.[/tex]
What is dissociation constant?
Kw is the dissociation constant or ionization constant of water.
The self-ionization of water will be
[tex]\rm 2 H_2O(l) = H_3O^+(aq) + OH^-[/tex]
The dissociation constant of the water at 25°C will be
[tex]\rm Kw = [H_3O^+][OH^-] = 1.0 \times 10^-^1^4[/tex]
Thus, the correct option is a. [tex]Kw =1.0\times 10^-^1^4.[/tex]
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How many atoms of each element are in the chemical formula NH4NO2?
1 nitrogen, 1 hydrogen, and 3 oxygen
O 1 nitrogen, 4 hydrogen, and 3 oxygen
2 nitrogen, 4 hydrogen, and 3 oxygen
O 5 nitrogen, 1 hydrogen, and 1 oxygen
PLEASE HELP I WILL MARK BRAINIEST ITS TIMED
Answer:
I assume air pollution.
Explanation:
If you incinerate something, usually fire or some kind of heating element is used. A byproduct of fire and/or burning is smoke, which can pollute the air.
Answer:
A. Air pollution
Explanation:
In the incineration Factories they produce items And Air pollution
Rust has the same properties as iron
True
False
Answer:
false
Explanation:
One of the waste byproducts of a nuclear reactor using uranium-235 is strontium-90 with half-life of about 28 years. If we have 100 pounds of this radioactive waste:
Answer:
(a) 140 years
(b) 3.125 pounds
Explanation:
QuestIons
(a) How long is five half-life
(b) How much radioactive strontium is left after five half-life
Given that:
Half-life is about 28 years; &
There are 100 pounds of this radioactive waste
Five half-life will be;
= 28 × 5
= 140 years
The amount of radioactive remaining after five half-life is:
[tex]= 100 \times( \dfrac{1}{2}) ^5[/tex]
= 100 × 0.03125
= 3.125 pounds
A chemical reaction in a lab experiment actually produces 1.23mol of BeBr2. The theoretical yield is 220g. To two decimal places, what is the percentage yield
Answer:
Percent yield = 94.62%
Explanation:
Given data:
Actual yield of BeBr₂ = 1.23 mol
Theoretical yield of BeBr₂ = 220 g
Percent yield = ?
Solution:
Theoretical yield in moles:
Number of moles = mass/molar mass
Number of moles = 220 g/168.82 g/mol
Number of moles = 1.30 mol
Percent yield:
Percent tiled = actual yield / theoretical yield × 100
by putting values,
Percent yield = 1.23 mol / 1.30 mol × 100
Percent yield = 0.9462 × 100
Percent yield = 94.62%
A complex absorbs photons with an energy of 4.10×10^−19 J. What is the wavelength of these photons? If this is the only place in the visible spectrum where the complex absorbs light, what color would you expect the complex to be?
Answer:
483 nm corresponds to blue light hence the complex will appear orange.
Explanation:
Using the formula;
E= hc/λ
Where;
E = energy of the photon
h = Plank's constant (6.6*10^-34Js)
c = Speed of light (3*10^8 ms-1)
λ = wavelength
λ = hc/E
λ = 6.6*10^-34 * 3*10^8/4.10×10^−19
λ = 4.83 * 10^-7 or 483 nm
483 nm corresponds to blue light
Using the colour wheel approach, if a complex absorbs blue light, then it will appear orange.
How are the cells in our bodies organized? Cells are organized into ______ , _____
, and
_____ systems?
quick answer pls!
Answer:
Cell --> Tissues --> Organs ---> Organ System ---> Organism
Select the correct answer.
Which of the following might cause chemical contamination when used near food?
A.
furniture polish
B.
steel can
Ос.
glass container
OD. plastic bag
Reset
Next
Match the definition with the correct term: 1/12th the mass of a carbon-12 atom.
Answer:
hydrogen atom but see the note below.
Explanation:
This is either the most common hydrogen ion or a hydrogen atom. It cannot be either of hydrogen's isotopes.
11.
A sample of TNT, C-H5N306, has 7.30 1021 nitrogen atoms. Determine the numbers of
hydrogen atoms in this sample of TNT.
021
Answer:
1.22 × 10^22 H atoms
Explanation:
From this question, TNT has the chemical formula: C-H5N306. The number of nitrogen atoms in the TNT substance is said to be 7.30 × 10^21 atoms.
The number of hydrogen atoms in the same TNT substance can be got using mole ratio. Based on the chemical formula, the mole ratio of hydrogen to nitrogen is 5:3 i.e. H5N3.
This means that;
Number of atoms of hydrogen = 5/3 of the number of atoms of nitrogen.
Hence, number of H atoms = 5/3 × 7.30 × 10^21
number of H atoms = (7.30 × 5/3) × 10^21
number of H atoms = (36.5/3) × 10^21
number of H atoms = 12.1666 × 10^21
number of H atoms = 1.2166 × 10^22 atoms.
Approximately, number of H atoms in TNT is 1.22 × 10^22 atoms.
17 Which changes decrease the rate of reaction between magnesium and air?
1.heating the magnesium to a higher temperature
2.using a higher proportion of oxygen in the air
3.using magnesium ribbon instead of powdered magnesium
A 1, 2 and 3
B 1 only
C 2 only
D 3 only
Using magnesium ribbon instead of powdered magnesium decrease the rate of reaction between magnesium and air.
What is rate of reaction?Rate of reaction tells about the duration of the completion of the reaction.
Rate of any reaction is directly proportional to the concentration and surface area of the reactant, temperature, catalyst, no. of collision, activation energy, etc.
So, if we magnesium in the ribbon instead of powdered magnesium the surface area of the reactant side decreases which results in the decrease of the rate of reaction.
Hence, option (D) is correct i.e. rate of reaction decreases on using magnesium ribbon instead of powdered magnesium.
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100
80
100 mL
water vapor
Which statement describes what will happen if a student
pushes the plunger
to compress the water vapor?
A. The total number of water particles will increase.
B. The amount of energy in the water particles will decrease.
C. The amount of empty space between the water particles will
decrease.
O D. The total volume of the water particles will increase.
I will mark brainliest
Answer: c (the amount of empty space between the water particles will decrease)
Explanation: i got it right:)
Question 5
2 pts
To determine the density of an irregularly shaped object, a student immersed the object in 32.2 mL of water in a graduated cylinder, causing the level of the water to rise to 37.8 ml. If the object had a mass of 12.4 g, what is the density of the object?
O 0.32 g/mL
O 1.4 g/mL
O 3.4 g/mL
O 2.2 g/mL
Help quick right answer gets brainliest !!
Answer:
Explanation:
2.2 g/mL is the answer.
Describe the liquid state of matter and give an example besides water.
If atomic size is the distance from the nucleus to the valence electrons, does the size of the atom get bigger or smaller as you go from period 1 to 3? Explain?
Example of market structures of monopoly
Answer: A monopoly is the absence of competition in the market.
Explanation:
In such circumstances, the market creates a monopoly of one producer who takes huge capital and dictates prices. An example of a monopoly on the market is the existence of only one company that makes up the entire economic branch. In such circumstances, the monopolist can increase the product's price without losing the entire sale, i.e., operating successfully. In that situation, the monopolist remains the only one on the market, and the competition has no access to the market.
Which energy source releases the most carbon dioxide?
O solar
O wind
O nuclear
O coal
Answer:
Coal
Explanation:
Coal is by far the worst emitter, followed by natural gas, with solar, wind and nuclear all low-carbon.
Coal, a non-renewable energy source releases the most carbon dioxide into the atmosphere.
What are energy sources?Energy sources refers to the various sources in which energy for man's needs are obtained.
There are two types of energy sources:
Renewable energy sourcesNon-renewable energy sourcesThe non-renewable energy sources such as coal release large amounts of carbon dioxide until The atmosphere.
Therefore, Coal, a non-renewable energy source releases the most carbon dioxide into the atmosphere.
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Describe the process of dimensional analysis and explain why it is so useful in chemical problem solving.
Answer:
Dimensional Analysis (also called Factor-Label Method or the Unit Factor Method) is a problem-solving method that uses the fact that any number or expression can be multiplied by one without changing its value. It is a useful technique.
if an atom has 15 protons and a mass of 31 how many neutrons will it have
Answer:
16 neutrons
Explanation:
now that protons are equal to electrons, there are 15 electrons. The mass is equal to 31.0, which is the ≡ of protons and ≡ neutrons added together. To find the number of neutrons, subtract the atomic # from the total mass #. 31-15=16 this would be equal to 16 now that the atomic has 31 and the mass is 15 subtract them ... you would get 16 neutrons inside the nucleus.
hope this helped ((((: if it did then please mark brainliest and have a wonderful day d:
Answer:
16
Explanation:
To find the neutrons, it's always mass-atomic number. Since the atomic number for an atom is always the protons, it's really mass-protons.
31-15=16
is pure water a solution
Answer: No because a solution is a homogeneous MIXTURE of two or more substances. Water is a pure substance. It is made of hydrogen and oxygen, but shares none of their properties. So it’s pure.
Explanation:
What do the rows in the Periodic Table tell us?
Answer:
The rows tell you how many shells there are of the atom.
please one more last help me on my task to go on baby corp
Answer:?
Explanation: i'm confused with this and i know i should be writing this in comments but if you can explain me the question maybe i could help you
hydrocarbon structures methopane
1. a metal with 3 valence electrons, used in cans.
2. a period 3 element that will not react naturally.
3. has 5 valence electrons and in period 3.
4. the most reactive metal.
Answer:
.
Explanation:
1. aluminum
2. argon
3. phosphorus
4. francium
I cant really explain this one
Zuzana tests a common household substance and finds that it has a pH of 3.
What type of substance is in the scenario?
acidic
basic
salt
neutral
pH is a measurement of amount of hydronium ion H₃O⁺ in a given sample. More the value of hydronium ion concentration, more will be the solution acidic. The given substance is acidic. The correct option is option A.
What are acid and base?Acid is a solution which releases H⁺ hydrogen ion when dissolved in water. Base are the solution which releases hydroxide ion OH⁻ ion when dissolved in water. The pH of acid is between 0-7 on pH scale while for base pH range is from 7-14.
On subtracting pH from 14, we get pOH which measures the concentration of hydroxide ion in a given solution. pH depend on the temperature. At room temperature pH scale is between 0 to 14. pH of neutral solution is 7.
Therefore, the given substance is acidic. The correct option is option A.
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How many moles of sulfate ions are in 756.91 mg of iron (III) sulfate?
Answer:
1 Answer. 1 mole of ferric sulfate contains 2 moles of iron, and 12 moles of oxygen atoms, and three moles of sulfate ions.Sep 29, 2016
Explanation:
Which of the following best defines an allotrope?
Question 1 options:
Crystalline forms
Carbon atoms
Different forms of the same element
Similar bonding arrangements between atoms
Answer:
hi buddy!! here is ur ans: carbon atoms
The formula for calculating power is work divided by time (power = work + time). What are two ways of stating the same relationship?
work = power + time
nwork s power x time
power
time = work x power
Opower workx time
time
Work
Answer:
See the answer below
Explanation:
The formula for calculating power is such that;
power = work/time
Two ways to restate the relationship between the 3 variables would be to make time and work the subject of the formula respectively.
1. When time if made the subject of the formula;
time = work/time
2. When work is made the subject of the formula;
work = power x time
I just wanted to say you guys on this app are no help. I have asked 4 question sin the past 1-2 hours and not one has been answered. If you know a lot about Chemistry please help me.