Answer:
In addition, the number of valence electrons present in the elements of these groups denotes the group. The valence electrons present in their elements reflect their particular group, which is why they are termed representative elements.
Explanation:
Name the fundamental unit involved in the derived unit joule?
Answer:
Energy
Explanation:
Write a neutralization reaction to form the salt k2so4
H2SO4 + 2KCL ----------› K2SO4 + 2HCL
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In a lab experiment, the decay of a radioactive isotope is being observed. At the beginning of the first day of the experiment the mass of the substance was 200 grams and mass was decreasing by 11% per day. Determine the mass of the radioactive sample at the beginning of the 10th day of the experiment. Round to the nearest tenth (if necessary).
Answer:
The correct answer is - 62.36 g.
Explanation:
Given:
Mass of substance - 200
decreasing rate - 11% per day
mass at the beginning of the 10th day - ?
Solution:
F(x) = 200*(1 - 11)^x
here x the time
F(x) = 200* (0.89)^10
= 200*0.3118
= 62.3634
Thus, the correct answer is 62.36 g.
How many molecules are in 0.0230 grams of C3H6?
Se tiene una solución acuosa 2M de carbonato de potasio. Expresar su concentración en %p/v y Normalidad.
Answer:
Normalidad = 4N
%p/V = 27.6%
Explanation:
La solución 2M de carbonato de potasio contiene 2moles de carbonato por litro de solución. La normalidad son los equivalente de carbonato de potasio (2eq/mol) por litro de solución:
2moles * (2eq/mol) = 4eq / 1L = 4N
El porcentaje peso volumen es el peso de carbonato en gramos dividido en el volumen en mL por 100:
%p/V:
Masa K2CO3 -Masa molar: 138.205g/mol-
2moles * (138.205g/mol) = 276g K2CO3
Volumen:
1L * (1000mL/1L) = 1000mL
%p/V:
276g K2CO3 / 1000mL * 100
%p/V = 27.6%Which statement about Niels Bohr’s atomic model is true?
Answer:
Each orbit has a specific energy level.
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The specific heat capacity of water is 4.186 J/g °C
Calculate the temperature change when 8000 J of heat is added to 3g of water.
Use the equation q=mcT
Answer:
Solution given:
specific heat capacity of water [c]4.186 J/g °C
temperature[∆T]=?
mass[m]=3g
heat[Q]=8000J
we have
Q=mc∆T
8000=3*4.186*∆T
∆T=8000/12.558
∆T=637.04°C
the temperature change is 637.04°C.
The energy of motion is called kinetic energy ? True or false
Answer:
True
Explanation:
Trust me
Answer:
True. Kinetic energy is the energy of motion. All moving objects have kinetic energy. When an object is in motion, it changes its position by moving in a direction: up, down, forward, or backward.
how many moles of hydrogen ions are present in a 2L solution with a pH of 2.75
We are given:
Volume = 2 L
pH = 2.75
Finding the concentration required:
we know that pH is just the negative log of the hydrogen ion concentration
pH = -log[H⁺]
we are given that the pH is 2.75
2.75 = -log[H⁺]
log[H⁺] = -2.75 [multiplying both sides by -1]
[tex]10^{log[H]} = 10^{-2.75}[/tex]
[H⁺] = 1.78 * 10⁻³ Molar
Number of moles of Hydrogen ions:
[H⁺] = 1.78 * 10⁻³ Molar
which means that there are 1.78 * 10⁻³ moles of hydrogen ions in 1 liter solution
1.78 * 10⁻³ moles / L
multiplying and dividing by 2, we get:
3.56 * 10⁻³ moles / 2 L
Hence we need 3.56 * 10⁻³ moles of hydrogen ions
Answer:
3.556x 10^-3mol
Explanation:
Using pH =-log [ H+], we can calculate the concentration of the hydrogen Ions.
pH =-log [ H+], pH = 2.75
2.75 = -log[H+], taking antilog of both sides
10^ — 2.75 = [H+]
[H+] =1. 778 x 10^-3M
Now that we have the concentration and also knows the volume, we can use the relation
Moles = concentration X volume
= 1. 778 x 10^-3M x 2L = 3.56x 10^-3mol
The moles of the hydrogen Ions is 3.56x 10^-3mol
If you sprain your ankle and place a cold pack on it, how does the motion of molecules in your ankle change?
Answer:
that heat energy speeds up the motion of the particles and the temperature of the reaction
Explanation:
HOPE IT HELPS
When we place an ice pack on a sprained ankle, the blood flow is reduced which prevents further swelling, ice reduces the blood flow which is necessary when the ankle is injured.
What happens after placing an ice pack?The flow of blood and the lymph vessel is limited or decreased after applying an ice pack, this is an immediate first aid to be given to the injured person
After 2-3 days of the injury, a hot pack should be applied to increase the blood flow and the lymph flow for an activity.
Hence, the molecule flow is reduced after applying an ice pack to the sprained ankle
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What is the final concentration when 275 mL of 20.0 % W/V hydrogen peroxide solution is diluted to 1.000 L?
20.0 % W/V
0.30 % W/V
55.0 % W/V
5.50 % W/V
Answer:
20.0% w/v A
Explanation:
A 20.0 w/V...
At the carnival, a baby was given a helium balloon whose
pressure equaled the atmospheric pressure at the carnival
which was 102.7 kPa. However, the baby wasn't paying
attention and the balloon floated away into the troposphere
where the atmospheric pressure is 97.8 kPa. What is the
positive difference between the pressure in the balloon and
the pressure of the troposphere in atm?
atm
Answer: 0.048 kPa
Explanation: no clue i just looked it up you’re welcome y’all:)
Si de una caja de gelatina de 30g, se obtiene 5 porciones. Cuantas cajas y cuantos gramos se requieren para preparar 100 porciones.? respuestas concretas por fis
Answer:
20 cajas - 600 gramos
Explanation:
Veamos los datos informados:
1 caja → 5 porciones
1 caja → 30 g
Si queremos preparar 100 porciones, indudablemente necesitamos:
100 porciones . 1 caja / 5porciones = 20 cajas
Finalmente ya sabemos que una caja tiene 30 g
Entonces, si tenemos 20 cajas . 30 g / 1 caja = 600 g
En conclusión:
Necesitamos una masa total de 600 gramos en 20 cajas
When you perform a stoichiometry calculation, you are determining the ...
A) actual yield
B) theoretical yield
C) percent yield
Answer:
B) Theoretical
Explanation:
Just did the question
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 is used to observe things, like cells, that are too small to see with the naked eye.
Answer:
a microscope is used to see little things the naked eye can't
A solution contains 35.00 g of sodium chloride in 100. G of water at 45.0C. How could this solution be described
Answer:
It is unsaturated
Explanation:
A solution is said to be unsaturated when it contains less solute than it can normally hold at a given temperature.
The solubility of NaCl remains fairly independent of temperature hence the line for the solubility of NaCl remains fairly flat in the solubility curve.
The solubility of NaCl is about 36 g of NaCl in 100g of water. Hence a solution that contains 35.00 g of sodium chloride in 100 g of water at 45.0C is unsaturated.
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Answer:
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Explanation:
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HELPPP!!!
The emission of electromagnetic energy from an atomic nucleus is called_______
decay.
Gamma decay, type of radioactivity in which some unstable atomic nuclei dissipate excess energy by a spontaneous electromagnetic process. In the most common form of gamma decay, known as gamma emission, gamma rays (photons, or packets of electromagnetic energy, of extremely short wavelength) are radiated.
What volume of O2 at STP is required to oxidize 8.0 L of NO at STP to NO2? What volume of NO2 is produced at STP?
The balanced equation of the reaction is:
[tex]O_2 + 2 NO[/tex] ⇒ [tex]2 NO_2[/tex]
Every gas occupied 24 L in one mole in r.t.p. according to the equation:
[tex]24 \times n = V[/tex]
8/24=0.333 mol
2 moles of NO makes 2 moles of [tex]NO_2\\[/tex] so
0.333*24=8L
Which is the correctly balanced chemical equation for the reaction of KOH and H2SO4? Which is the net ionic equation for the reaction?
Answer:
See explanation
Explanation:
A balanced chemical reaction equation has the same number of atoms of each element on both sides of the reaction equation.
Hence, for the reaction between KOH and H2SO4, the balanced chemical reaction equation is;
H2SO4(aq) + 2KOH(aq) ---------> K2SO4(aq) + 2H2O(l)
Complete ionic equation;
2H^+(aq) + SO4^2-(aq) + 2K^+(aq) +2OH^-(aq) -------> SO4^2-(aq) + 2K^+(aq) + 2H2O(l)
Net ionic equation;
2H^+(aq) + 2OH^-(aq) -------> 2H2O(l)
what makes a compound a pure substance
Answer:
Compounds contain more than one type of material. Yet both compounds and elements are considered pure substances.
Pure compounds are created when elements combine permanently, forming one substance
Extra:
So, a mixture can be separated into its original components, while a pure compound cannot.
Carbon monoxide has _____of oxygen.
One atom
Zero atoms
Two atoms
30 ml of gas is changed from 4 atm to 2 atm what is the new volume
Answer:
[tex]\boxed {\boxed {\sf 60 \ mL}}[/tex]
Explanation:
In this problem, volume and pressure are changing, so we use Boyle's Law. This states that the volume of a gas is inversely proportional to the pressure. The formula for this law is:
[tex]P_1V_1=P_2V_2[/tex]
Originally the gas has a volume of 30 milliliters and a pressure of 4 atmospheres.
[tex]4 \ atm * 30 \ mL=P_2V_2[/tex]
The pressure is changed to 2 atmospheres, but the new volume is unknown.
[tex]4 \ atm * 30 \ mL = 2 \ atm *V_2[/tex]
We want to solve for the new volume (V₂). It is being multiplied by 2 atmopsheres. The inverse operation of multiplication is division, so we divide both sides by 2 atm.
[tex]\frac{4 \ atm * 30 \ mL}{ 2 \ atm}= \frac{ 2 \ atm *V_2}{2 \ atm}[/tex]
[tex]\frac{4 \ atm * 30 \ mL}{ 2 \ atm}= V_2[/tex]
The units of atmospheres (atm) cancel.
[tex]\frac{4 * 30 \ mL}{ 2 }= V_2[/tex]
[tex]\frac{120 \ mL}{2}= V_2[/tex]
[tex]60 \ mL= V_2[/tex]
The new volume of the gas is 60 milliliters.
when electrical energy is converted into any other deform of energy, the total amount of energy
The empirical formula for a compound is CH2. If n is a whole number, which shows a correct relationship between the molecular formula and the emperical formula.
Answer:
D)subscript of C in molecular formula = n x subscript of C in empirical formula
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
.The empirical formula for a compound is CH2. If n is a whole number, which shows a correct relationship between the molecular formula and the empirical formula? a)<br /><br /> empirical formula mass / molecular mass = n<br /><br /> B) molecular mass = element mass / empirical formula mass ´ 100<br /><br /> c) subscript of H in empirical formula = 2  subscript of H in molecular formula<br /><br /> D) subscript of C in molecular formula = n  subscript of C in empirical formula<br /><br />
An empirical formula can be regarded as "shorten form" of a molecular formula. Instance of this is
A compounds CH4, C2H8, C4H12... with empirical formula of CH4. In this case a constant "n" represent the difference that exist between empirical formula and molecular formula, "n" which is a whole number, molecular formula is the numerator.
Therefore, subscript of C in molecular formula = n x subscript of C in empirical formula
need help asap electrons
positively charged, subatomic particles found in the nucleus of the atom
2. metals
elements with properties intermediate between those of metals and nonmetals
3. period
a homogeneous mixture whose particles are too small to reflect or scatter light
4. compound
two or more elements that have chemically combined
5. solution
elements that are malleable, polish to a luster, conduct heat and electricity well and tend to lose electrons in a chemical reaction
6. protons
a vertical column on the periodic table
7. group
a horizontal row on the periodic table
8. metalloids
negatively charged, subatomic particles
Answer:
need help asap electrons
positively charged, subatomic particles found in the nucleus of the atom
2. metals
elements with properties intermediate between those of metals and nonmetals
3. period
a homogeneous mixture whose particles are too small to reflect or scatter light
4. compound
two or more elements that have chemically combined
5. solution
elements that are malleable, polish to a luster, conduct heat and electricity well and tend to lose electrons in a chemical reaction
6. protons
a vertical column on the periodic table
7. group
a horizontal row on the periodic table
8. metalloids
negatively charged, subatomic particles
Explanation:
The Sun has six regions or layers. Identify the Sun's layers, beginning with the innermost and moving out.
1. Innermost
convective zone
2. 2nd innermost
corona
3. 3rd innermost
core
4. 4th innermost
photosphere
5. 5th innermost
chromosphere
6. Outermost
radiative zone
Answer:
Beginning from the innermost layer and moving towards the outermost of the sun that has six layers.
1. Innermost layer is the core: All the energy of the sun comes from core. Here hydrogen and helium are components that are present.
2. Radiative zone: The high-energy photons are move from the innermost core to the second innermost radiative zone.
3. Convective zone: It is a comparatively cooler layer to the core and radiative zone.
4. Photosphere: It is the 4th innermost region with sunspots and called the magnetic field of the sun.
5. Chromosphere: This red color layer with filaments of gas is cooler than the photosphere.
6. Corona: It is the outermost layer of the sun and the temperature is much higher here.
Lithium chloride + Iron → ?
Answer:
Lithium chloride + Iron
No reaction takes place, because lithium is more reactive than iron, so Iron cannot displace lithium from its solution.
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How many moles are in 3.90 x1030 atoms of Zn?