Answer:
Por ejemplo, el Litio se ubica en el grupo 1A, entonces tiene 1 electrón de valencia.
Explanation
Excepto los grupos 3-12 (los metales de transición), el dígito de las unidades del número de grupo identifica cuántos electrones de valencia se pueden asociar con un átomo neutro de un elemento listado en dicha columna.E
please help me anyone its due today thank you !
true
Explanation:
Ecothermic reactiions are reactions or processes that release energy. From heat or light.
A.True
Explanation:
Reactants+Products+Energy
What does it mean when a compound is 'soluble in water?
A. It does not dissolve in water.
OB. It dissolves in water.
O C. It forms a precipitate in water.
O D. It has water molecules attached to it.
B. It dissolves in water.
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Answer:
B it dissolves in water
Explanation:
Their molecules bond to water molecules
For an object to remain at rest which of the following statements must be true
Answer:
An object that is at rest will stay at rest unless a force acts upon it. An object that is in motion will not change its velocity unless a force acts upon it. This is known as uniform motion. An object continues to do whatever it happens to be doing unless a force is exerted upon it.
Explanation: NEWTONS laws of motion
aluminum oxide is an ionic substance with formula al2o3. explain what this formula means.
Answer:
the 2 means there are 2 al and the 3 means there are 3 o
Explanation:
I hope this helps
One litre of hydrogen at STP weight 0.09gm of 2 litre of gas at STP weight 2.880gm. Calculate the vapour density and molecular weight of gas.
Answer:
we know, at STP ( standard temperature and pressure).
we know, volume of 1 mole of gas = 22.4L
weight of 1 Litre of hydrogen gas = 0.09g
so, weight of 22.4 litres of hydrogen gas = 22.4 × 0.09 = 2.016g ≈ 2g = molecular weight of hydrogen gas.
similarly,
weight of 2L of a gas = 2.88gm
so, weight of 22.4 L of the gas = 2.88 × 22.4/2 = 2.88 × 11.2 = 32.256g
hence, molecular weight of the gas = 32.256g
vapor density = molecular weight/2
= 32.256/2 = 16.128g
hence, vapor density of the gas is 16.128g.
Explanation:
How are elliptical galaxies different from spiral galaxies?
a. They contain older stars and less gas and dust.
b. They contain younger stars and more gas and dust.
c. They are bigger than spiral galaxies.
d. They are smaller than spiral galaxies.
Answer:
A. They contain older stars and less gas and dust.
Explanation:
There are three types of galaxies:
elliptical galaxiesspiral galaxieslenticular galaxiesElliptical galaxies are galaxies shaped like an ellipse, while spiral galaxies consist of a flat, rotating disk that contains stars, gas, and dust, and a central concentration of stars called the bulge.
The difference between elliptical and spiral galaxies is in the amount of gas and dust they contain. Spiral galaxies contain large amounts of gas and dust, which means that new stars are born very often. This makes them brighter than relatively dim elliptical galaxies, which contain less gas and dust. This is why fewer new and brighter stars are born in elliptical galaxies, leaving them with older, dimmer stars.
melting is considered a(n) ___ change because energy is gained by the substance as it changes state
A. Physical.
B. Chemical.
C. Volume.
D. Dynamic.
What is the mass of 1.794 mol Ba(NO3)2?
Explanation:
Molar mass of Ba(NO3)2 = 261.3368 g/mol
please help it’s due today
The reaction K(s) + 2H2O(l) → 2KOH(aq) + H2(g) is a decomposition reaction.
True
False
Answer:
Yes it is true reaction
Answer: yes it is true
Explanation: i took the test
what is polling in chemistry?
Answer:
Polling is a method used for the purification of copper or tin which contains oxide impurities
Answer:
Polling is used for the purification of copper or tin which contains oxide impurities. The impure metal is melted and stirred with green logs of wood. The heat of molten metal makes the green logs to liberate hydrocarbon gases which in turn reduce the metal oxide into metal.
What sport was used to demonstrate Newton's 3 Laws?
Which of the following set of atoms has the largest electronegativity difference?
a. H and P
b. N and C
c. Li and O
d. Cl and Ca
Answer:
C
Explanation:
Li has an electronegativity of 0.98, O has an electronegativity of 3.44. 3.44-0.98= 2.46 electronegativity differnece :)
P4 (s) + Cl2 (g) → 4PCl3 (l)
Practitioners of the branch of alternative medicine known as homeopathy claim that very dilute solutions of substances can have an effect. Is the claim plausible? To explore this question, suppose that you prepare a solution of a supposedly active substance, X, with a molarity of 0.10 molL1 . Then you dilute 10. mL of that solution by doubling the volume, doubling it again, and so on, for 90 doublings in all. How many molecules of X will be present in 10. mL of the fi nal solution? Comment on the possible health benefi ts of the solution.
Answer:
a. 4.865 × 10⁻⁷ molecules. b. The possible health benefits of the drug might be minimal or non-existent.
Explanation:
a. Since we have 0.10 mol/L and 10 mL of solution, the number of moles in 10 mL of solution is n = CV where C = concentration and V = Volume. C = 0.10 mol/L and V = 10 mL = 0.01 L.
So n = CV = 0.10 mol/L × 0.01 L = 0.001 mol.
Since the initial volume of the solution is 10 mL and doubled, it is 2 × 10 mL = 20 mL. It is doubled again to 2 × 20 mL = 40 mL. It is doubled again to 2 × 40 mL = 80 mL. Our third doubling is thus 80 mL = 2 × 2 × 2 × 10 mL = 2³ × 10 mL. So the volume for our nth doubling is V = 2ⁿ × 10 mL. So four our 90 th doubling, the volume is V = 2⁹⁰ × 10 mL = 2⁹⁰ × 10 mL
Since we have 0.001 mol present, the concentration in this new volume is thus C' = 0.001 mol/2⁹⁰ × 10 mL.
So the number of moles in 10 mL of this solution is thus n = 0.001 mol/(2⁹⁰ × 10 mL) × 10 mL = 0.001/2⁹⁰ mol
To find the number of molecules of X present we use, number of moles, n = number of molecules, N/Avogadro's number of molecules, N'
n = N/N'
N = nN'
= 0.001/2⁹⁰ mol × 6.022 × 10²³ molecules/mol
= 8.078 × 10⁻³¹ × 6.022 × 10²³
= 48.65 × 10⁻⁸
= 4.865 × 10⁻⁷ molecules.
b. Since the number of molecules of X present in 10 mL solution of the final diluted solution is 4.865 × 10⁻⁷ molecules, this shows that the number of molecules of X is very little so, the possible health benefits of the drug might be minimal or non-existent.
What is the pressure of 64 grams of O2 in a 1L container at a temperature of 10°C?
2 The substance has a mass of 0.50 kg.
34 000 J of energy is transferred to the substance to completely melt it.
The temperature of the substance does not change during this time.
Calculate the specific latent heat of fusion of the substance.
Use an equation from the Equations List.
Answer:
68000J/kg
Explanation:
Given parameters:
Mass of the substance = 0.5kg
Quantity of heat transferred to the body = 34000J
Unknown:
Specific latent heat of fusion = ?
Solution:
The specific latent heat is usually involve in phase changes;
H = mL
H is the quantity of heat supplied
m is the mass
L is the specific latent heat
Insert the parameters and solve;
34000 = 0.5 x L
L = [tex]\frac{34000}{0.5}[/tex] = 68000J/kg
Which of the following is TRUE about when two atoms form a bond? a. Repulsion is greater than attraction b. Neither atoms will have a full valence shell c. Potential energy is at a minimum
Answer:
b: Neither atoms will have a full valence shell
Explanation:
I think sooo
does formaldehyde classified as a pure substance or a mixture
Answer:
pure substance
Explanation:
it is a naturally occuring compound
Answer:
Formaldehyde is a mixed substance. It is made up of Carbon, 2 Hydrogen, and an Oxygen.
Explanation:
The formula is CH2O
WILL GIVE BRAINLIEST how many moles are in 1.42x10^22 molecules of AlCl3?
3 is a subscript.
Answer: Many argue that modern chemical science began when scientists started ... Figure 3.2 The average mass of a chloroform molecule, CHCl3, ... 5.00gCu(molCu63.55g)(6.022×1023atomsmol)=4.74×1022atoms of copper
Explanation: hope this helps
what does light emission(color) tell us about elements?
Answer:
The color of the light emitted depends on the energies of the photons emitted, which are in turn are determined by the energies required to move electrons from one orbital to another. Those colors are as distinctive to each element as fingerprints are to people. Hope this helps
Answer:
The color of the light emitted depends on the energies of the photons emitted, which are in turn are determined by the energies required to move electrons from one orbital to another. Depending on the element you put in the flame, various different energies of photons (colors) will appear. Those colors are as distinctive to each element as fingerprints are to people.
Explanation:
A piece of silver is heated and added to a styrofoam cup calorimeter containing 26.0 mL (the density of water is 1 g/mL) of water at 19 oC. The water reaches a maximum temperature of 44 oC after the metal was added. If the specific heat of the silver is 0.240 J/g oC and it started at 93.8 oC
Answer:
m(Ag) = 227.5g
Explanation:
...what is the mass of the piece of silver?
The heat given for the piece of silver is the same heat that is absorbed for the water, that is:
m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)
m is mass of water in solution: 26.0mL = 26g of water
And m(Ag) is the mass of Ag, our incognite.
C is specific heat (0.240J/g°C for Ag), and 4.184J/g°C for water
ΔT is change in temperature (93.8°C - 44°C = 49.8°C) for Ag ad (44°C - 19°C = 25°C)
Replacing:
m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)
m(Ag)×0.240J/g°C×49.8°C = 26g×4.184J/g°C×25°C
m(Ag)* 11.952J/g = 2719.6J
m(Ag) = 227.5g
Why are molecular covalent compounds insoluble in water?
Answer:
Hope this will help.......
Explanation Covalent bonds are insoluble in water (H2O) , but covalent compounds are. This is because some organic compounds (covalent) contain the polar −OH group which can bond to a hydrogen ion to form water.
Most earthquakes and volcanoes occur in areas of the Pacific Ocean called "The Ring of Fire." What is the main reason for this?
Group of answer choices
Large numbers of people live in this area.
That area of the Earth is hotter than any other area.
Lithosphere plate boundaries are found in that area.
The weight of the ocean water forces magma to the surface.
Answer:
Lithosphere plate boundaries are found in that area.
Explanation:
Answer:
C is the right answer
Explanation:
Help pleasee I need help to write the formulas i’m so lost
Answer:
NH4
Explanation:
Gas laws mad question under it
Answer:
what are you asking tho?
Explanation:
Thx for the Free points tho.
4-How does the concentration of ions in a strong acid differ from a weak acid?
How is a "decay event' recorded
Which of the following best defines a basic solution?
When does nuclear fusion start during the life of a star?
Answer:
Try searching this on google
Explanation:
I might have an answer but I am not entirely sure sorry I really tried to help but there is also an app called socractic it also helps with questions
Once the temperature reaches 15,000,000 levels Celsius, nuclear fusion takes location in the center, or core, of the cloud. The high-quality heat given off by means of the nuclear fusion technique motives the gasoline to glow creating a protostar. This is the first step in the evolution of a star.