Answer:
The elements of the same group have the same number of valence electrons, that is why they have similar properties
A 500-gram block of solid cheese is melted in a pot. Which is most likely be the mass of the cheese after it is melted?
pleaseeeeeeeeee answer
Answer:
due to the law of conservation of mass, the mass would stay the same.
Write the name of flame used In charcoal cavity test.why?
Answer:
the reducing flame also called the carburizing flame.
Explanation:
because it gets the oxides of the unknown salts
Which characteristic of a planet describes whether the planet has a thick or thin layer of gas?
Atmosphere
Moons
Rings
Surface composition
Answer:
Atmoshphere!
Explanation:
I took the test and got a 100%! :) Hope this helps, plz mark brainliest!
Which of the nine substances are made of three elements?
Answer: You are made of mostly 6 elements: Oxygen, Carbon, Hydrogen, Nitrogen, Calcium, and Phosphorus. Some of these elements combine to form compounds in your body.
Explanation:
Revise this statement to make it true:
Running water makes rock edges very sharp and pointy.
NEED HELP NOW PLEASE!! WHOEVER ANSWERS FIRST GETS BRAINIEST!!! No links or I’m reporting your answer.
Answer:
Running water makes rock edges very dull because of erosion.
Explanation:
hope this helps ^_^
Why is the distance traveled between seconds 0 and 1 less than the distance traveled between 2 and 3 sceonds
Answer:
The ball speeds up
Explanation:
Which of the following pairs of elements will combine to produce a covalent bond?
1-Hydrogen and chlorine
2-Magnesium and oxygen
3-Lithium and bromine
Answer:
Hydrogen and Chlorine
ie HCL
The pairs of chemical elements that will combine to produce a covalent bond is: 1. Hydrogen and chlorine.
In Chemistry, the three (3) main types of chemical bonds include:
Ionic bonds: Lithium and bromineHydrogen bonds: Hydrogen and oxygen.Covalent bonds: Hydrogen and chlorine.A covalent bond can be defined as a type of bond that typically involves the sharing of electrons between the atoms of a chemical element.
For example, the type of bond that is produced (formed) between hydrogen atoms and a chlorine atom is a covalent bond.
The hydrogen atom shares it single electron with a chlorine atom that is having seven (7) valence electrons to produce an inert gas such as hydrochloric acid (HCL).
In conclusion, the pairs of chemical elements that will combine to produce a covalent bond is hydrogen and chlorine.
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31. Solve this Gibbs' Free Energy Equation:
For a reaction at 200 K, the Delta H has a value of 250 kJ and the Delta S has a value of 0.100 kJ. 1s
the reaction spontaneous or not spontaneous?
Answer:The standard Gibbs energy change at 300K for the reaction 2A⇔B+C is 2494.
Explanation:
ΔG = free energy at any moment.
ΔGo = standard-state free energy.
R is the ideal gas constant = 8.314 J/mol-K.
T is the absolute temperature (Kelvin)
lnQ is natural logarithm of the reaction quotient
The diffusion of matter and energy in a liquid is slower than diffusion in a gas
True
O False
Use a scientific calculator to calculate [H+] for the following pH values:
7 (a neutral solution)
5.6 (unpolluted rainwater)
3.7 (first acid rain sample in North America)
How many times higher is the concentration of H+ in the Hubbard Brook sample than in unpolluted rainwater?
Answer:
pH = 7 ⇒ [H⁺] = 1.0x10⁻⁷ M
pH = 5.6 ⇒ [H⁺] = 2.5x10⁻⁶ M
pH = 3.7 ⇒ [H⁺] = 2.0x10⁻⁴ M
H⁺ concentration in the Hubbard Brook sample is 80 times higher than in unpolluted rainwater.
Explanation:
To answer this problem we need to keep in mind the definition of pH:
pH = -log[H⁺]Meaning that after isolating [H⁺] we're left with:
[H⁺] = [tex]10^{-pH}[/tex]Now we proceed to calculate [H⁺] for the given pHs:
pH = 7 ⇒ [H⁺] = [tex]10^{-7}[/tex] = 1.0x10⁻⁷ MpH = 5.6 ⇒ [H⁺] = [tex]10^{-5.6}[/tex] = 2.5x10⁻⁶ MpH = 3.7 ⇒ [H⁺] = [tex]10^{-3.7}[/tex] = 2.0x10⁻⁴ MFinally we calculate how many times higher is [H⁺] when pH = 3.7 than when pH = 5.6.
2.0x10⁻⁴ / 2.5x10⁻⁶ = 80Answer:
1. 7 (a neutral solution)
Answer: 10-7= 0.0000001 moles per liter
2. 5.6 (unpolluted rainwater)
Answer: 10-5.6 = 0.0000025 moles per liter
3. 3.7 (first acid rain sample in North America)
Answer: 10-3.7 = 0.00020 moles per liter
The concentration of H+ in the Hubbard Brook sample is 0.00020/0.0000025, which is 80 times higher than the H+ concentration in unpolluted rainwater.
Explanation: -
Which statement correctly describes the relationship between air temperature and air pressure?
-Warm air rises, creating an area of low pressure.
-Cool air sinks, creating an area of low pressure.
-Warm air sinks, creating an area of low pressure.
-Cool air rises, creating an area of low pressure.
Answer:
-Warm air sinks, creating an area of low pressure.
Explanation:
Heat will weigh more, than cool air!
What is the density of a book with a mass of 60g and a volume of 20 cm3? *
Answer:
[tex]3 g/cm^{3}[/tex]
Explanation:
Density is a measure of a substance's mass over its volume.
d = m/v
Therefore d = 60g/20cm3 = 3 g/cm3
If you have 12 atoms of hydrogen before a chemical reaction, how many atoms of hydrogen will be present
Answer:
12 atoms of hydrogen will be present in the product
Explanation:
12 atoms of hydrogen will be present in the product because the law of conservation of mass states that mass is neither created nor destroyed in chemical reactions.
The law of conservation states that the mass of the element remains the same during the course of the reaction.
The law of reaction conformed by the following:-
Mass of reactant Mass of productAccording to the question, the amount of hydrogen is 12 atoms in the reactant and the amount will remain the same at the end of the reaction, which is a product that is 12 atoms
Hence, the amount remains the same in the reaction that is 12 atoms
For more information, refer to the link:-
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Did anyone do this worksheet (science)
when a rotting log was turned over, pill bugs, termites , ants , fungi , and earthworms were living there. the termites represent ____ in its
a. an environment
b. a population
c. a niche
d. an abiotic factor
A 25.00 mL sample of the ammonia solution
was accurately diluted to 250.0 mL. A 25.00mL
aliquot of the diluted ammonia solution was
placed in a conical flask. Indicator was then added
and the solution was titrated with 0.208 molL-1
hydrochloric acid. The indicator changed colour
permanently when 19.64 mL of the acid had been
added. Calculate the concentration of ammonia in
the original solution.
Answer:
1.634 molL-1
Explanation:
The mol ration between NH3 and HCl is 1 : 1
Using Ca Va / Cb Vb = Na / Nb where a = acid and b = base
Na = 1
Nb = 1
Ca = 0.208 molL-1
Cb = ?
Va = 19.64 mL
Vb = 25.00mL
Solving for Cb
Cb = Ca Va / Vb
Cb = 0.208 * 19.64 / 25.0
Cb = 0.1634 molL-1 (Concentration of diluted ammonia solution)
Using the dilution equation;
C1V1 = C2V2
Initial Concentration, C1 = ?
Initial Volume, V1 = 25.00 mL
Final Volume, V2 = 250 mL
Final Concentration, C2 = 0.1634 molL-1
Solving for C1;
C1 = C2 * V2 / V1
C1 = 0.1634 * 250 / 25.00
C1 = 1.634 molL-1
What is the volume of an object that has a mass of 5.80 g and a density of 6.35 g/mL?
Answer:
1.09 mL
Explanation:
Density is a measure of a substance's mass over its volume.
d = m/v
We can rearrange the equation to solve for volume, using algebra.
v = d/m
Therefore v = 6.35/5.80 = 1.09 mL
When naming an acid, which of the following is true?
chlorite changes to chloric acid
chlorate changes to chloric acid
none of these is true
chlorate changes to chlorous acid
Answer:
chlorate changes to chlorous acid
before you retire in the evening, you sit down for a snack of milk and cookies. when you waken in the morning, you discover a carton of sour milk on the counter. knowing that milk sours if left in the refrigerator too long, has the reaction rate increased or decreased for the carton of milk on the counter? what has happened to its reaction time
Answer:
Increased
Explanation:
We know that the higher the temperature the higher the rate of reaction. This implies that as the temperature is increased, a reaction tends to proceed faster.
This follows from the collision theory, the higher the temperature, the higher the energy of the reacting particles hence they collide with each other faster and more effectively.
Thus the rate of reaction( or reaction time) for the carton of milk on the counter was increased.
Which feature separates watershed
Answer:
Ridges.
Explanation:
Watersheds are separated from one another by ridges. Ridges are elevated boundaries that divide watersheds.
I went for a walk the other day. I went four blocks east, then seven blocks south, then one block west and finally
eight blocks north
a.What distance did I travel?
b. What's my displacement?
Answer:
a) distance is 4+7+1+8=20 blocks
b) displacement is 10 blocks
Explanation:
find displacement: x and y
x axis displacement = 4-1 = 3 blocks
y axis displacement = -7+8= 1 block
displacement = the square root of 3^2 + 1^2
= 9+1 = 10 blocks.
You can find the angle of displacement with respect to the initial position using trig identities, if you wish.
potassium hydroxide , sodium chloride, sodium hydroxide ,calcium chloride , sodium bicarbonate write molecular formula
✧ [tex] \underline{ \underline{ \large{ \tt{A \: N \:S \: W \: E \: R}}}} : [/tex]
[tex] \underline{ \underline{ \large{ \text{Molecular \: Formulaes}}}} : [/tex]
⇾ [tex] \large{ \text{Potassium \: Hydroxide : K \: OH}}[/tex]
⇾ [tex] \large{ \text{Sodium \: Chloride : NaCl}}[/tex]
⇾ [tex] \large{ \text{Sodium \: Hydroxide : NaOH}}[/tex]
⇾ [tex] \large{ \text{Calcium \: Chloride : CaCl}}[/tex]
⇾ [tex] \large{ \text{Sodium \: Bicarbonate} : \tt{Na ( HCO)_{ 3} }}[/tex]
---------------------------------------------------------
☥ [tex] \underline{ \underline{ \large{ \tt{ \: E \: X\: P \: L\: A\: N \: A \: T \: I \: O \: N}}} }: [/tex]
[tex] \underline{ \underline{ \text{Writing \: a \: molecular \: formula}}} : [/tex]
To write a molecular formula , the following steps are usually adopted only when we know the symbol and valencies of elements and radicals present in a molecule.
Step 1 : First , the name of the compound is written.
Step 2 : The symbols of basic and acidic radicals are written side by side.
Step 3 : The valency of each radical is written at the right upper corner of the symbol. The valency of one radical is transferred to another radical and it is written on the right hand side at the bottom corner. If necessary , L.C.M of the valencies us taken to get a simple whole number.
Step 4 : If a compound radical takes part in the molecular formula , the radical is enclosed in brackets and the valency number is written on the right side of the bracket at the bottom of the formula.
For instance :
[tex] \text{Calcium \: \: \: \: \: \: Sulphate}[/tex] [ compound ]
1. [tex] \sf{Ca \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: SO_{4} }[/tex] [ Symbol of basic and acidic radicals ]
2.We know : Valencies of calcium and sulphate are 2 and 2 respectively
3. [tex] \sf{Ca_{2} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: (SO_{4} )_{2} }[/tex] [ Valencies are exchanged and compound radical is enclosed in bracket ]
4.[tex] \sf{CaSO_{4}}[/tex] [ L.C.M is taken to get molecular formula of calcium sulphate ]
Hope I helped ! ♡
Have a wonderful day / night ! ツ
☄ Let me know if you have any questions regarding my answer !
☥ [tex] \underline{ \underline{ \mathfrak{Carry \: On \: Learning}}}[/tex] !! ✎
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Why is there a hole in the ozone layer? What do you think the consequences of that hole are?
Answer:
There is a ozone layer because of the special atomphere and chemical conditions that takes place there. I think the consequences of that home area is the very low winter temperatures.
Answer:
There is a hole in the ozone layer because of the pollution on earth. Because of that the UV rays are easily entering the earth through that portion. The consequences of this can be cancers, global warming and disastrous storms.
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what is a molecule??
Answer:
molecule is a group of atoms bonded together representing the smallest fundamental unit of a chemical reaction
1 mole of any gas is equivalent to?
Answer:
22.4 L at standard temperature and pressure.
how many moles is 130g of cocl2
Answer:
1.3142 mol CoCl2
Explanation:
Well, to answer this we need to find out how many grams are in a single mole of CoCl2. Two find that we need to get the molar mass of CoCl2
Co = 28.0101 g Co per mole
Cl = 35.453 * g Cl per mole
28.0101 + 2 * 35.453 = 98.9161 g CoCl2 per mole
Now, we divide:
130/98.9161 = 1.3142 mol CoCl2
There are 1.31 moles in 130grams of cobalt chloride (CoCl2). Details about how to convert mass to moles can be found below.
How to calculate number of moles?The number of moles of a substance can be calculated by dividing the mass of the substance by its molar mass.
According to this question, there are 130g of CoCl2.
molar mass of CoCl2 = 28 + 35.5(2) = 99g/mol
moles = 130g ÷ 99g/mol
moles = 1.31 moles
Therefore, there are 1.31 moles in 130grams of cobalt chloride (CoCl2).
Learn more about number of moles at: https://brainly.com/question/14919968
Directions: Show all of your work for each of the following problems.
3. What is the % Ba in Ba(NO3)2?
4. What is the % of each element in Ni3(PO4)2?
5. What is the % of each element in Al2(CrO4)3?
6. What is the % of each element in (NH4)2(SO4)?
Answer:
3.Ba=24.Ni=2...PO4=35.Al=3...CrO4=26.NH4=1...SO4=2Pls 50 points right answer gets brainliest
Explain the meaning of thermal energy transfer and give specific examples of conduction, convection, and radiation.
Answer:
thermal energy: the part of total internal energy that can be transferred (a portion of the kinetic energy)
heat is the thermal energy that flows from one substance to another due to a temperature difference.
Thermal energy is measured in temperature change.
Thermal energy transfer stops when thermal equilibrium is achieved (Both substances at the same temperature).
conduction: Transfer of thermal energy through a solid object like heat transferring up a metal spoon from a hot cup of coffee.
convection: the transfer of thermal energy due to the movement of a liquid or gas caused by differences in temperature. Only in a fluid (liquid or gas). Breezes, ocean currents.
radiation: Transfer energy with or without matter. Warming from the Sun, microwave oven.
Answer:
Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas. Radiation is the transfer of thermal energy through thermal emission. Hope this helps!
Explanation:
Which element would be the most suitable to make a spoon that will melt in
your hot drinks?
A) aluminium
melting point: 660°C
boiling point: 2470°C
B) argon
melting point: -189°C
boiling point:-186°C
C) bromine
melting point: -7°C
boiling point: 59°C
D) gallium
melting point: 30°C
boiling point: 2400°C
E) lithium
melting point: 180°C
boiling point: 1330°C
F)mercury
melting point: -39°C
boiling point:357°C
Answer:
it's A) or E)
others are not suitable cuz their melting point is weak.
Answer:
Gallium
Explanation:
Because the melting point is low and the drinks are usually around 60-70 degrees Celsius so it wil melt
What is the correct formula for the missing product from the equation below:
Na2CO3(aq)
+
CaCl2 (aq)
> NaCl +
Answer:
CaCO3 (s)
Explanation:
This equation is a double replacement equation, which means that since Na and Cl and paired, Ca and CO3 will be paired.
Then, you look at the charge of each element and balance
Ca has a 2+ charge
CO3 has a 2- charge
The 2+ charge and the 2- charge will cancel so there is no need for a subscript or to balance the equation
The complete equation will be Na2CO3 (aq) + CaCl2(aq) -> NaCl (aq) + CaCO3 (s)
I hope this helps and have a great day!