Answer:
When elements combine in a chemical reaction to form compounds, their individual identity is lost. Thus, the properties of elements change when they form chemical bonds with other elements to form compounds. For example, the compound water is made up of water and hydrogen.
15
Select the correct boxes.
Which two elements have the same number of valence electrons?
Element
Atomic Number
barium
56
neon
10
silicon
14
carbon
6
Reset
Reset
Next
Answer:
barium and silicon has same valence electrons
Explanation:
barium-2,8,18,18,8,2
neon-2,8
silicon-2,8,2,2
carbon-2,4
Answer: both barium and silicone
Explanation:
it was an my exam
A sample of carbon dioxide gas at a pressure of 1.10 atm and a temperature of 20.6 C, occupies a volume of 19.2 L. If the gas is allowed to expand at a constant temperature to a volume of 24.3 L, the pressure of the gas sample will be ____ atm.
Answer:
P₂ = 0.87 atm
Explanation:
Given data:
Initial pressure = 1.10 atm
Initial volume = 19.2 L
Final volume = 24.3 L
Final pressure = ?
Solution:
The given problem will be solved through the Boyle's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
1.10 atm × 19.2 L = P₂ × 24.3 L
P₂ = 21.12 atm. L/ 24.3 L
P₂ = 0.87 atm
One glass of water is 85 degrees F and another is 40 degrees F. When an Alka Seltzer tablet is dropped into each glass, at the same time, which of the following describes the expected results? The 85 degree F glass will have an accelerated chemical reaction, because the water was warmer.
The 85 degree F glass will have an accelerated chemical reaction, because the water is cooler.
The 40 degree F glass will have an accelerated chemical reaction, because the water is cooler.
The 40 degree F glass will have an accelerated chemical reaction, because the water was warmer.
Answer:
The 85 degree F glass will have an accelerated chemical reaction, because the water was warmer.
Explanation:
The glass of water with the higher temperature will have an accelerated chemical reaction because the water is warmer.
The rate of chemical reaction is directly proportional to the temperature changes.
As temperature increases so is the reaction rate.
Temperature is directly proportional to the average kinetic energy of reacting particles. So, the glass water at a higher temperature will have a faster reaction. The elevated temperature ensures increase in frequency of colliding particles in the reaction.Please help me, Thank you!
Answer:
5
Explanation:
The electrons in the outermost shell are the valence electrons. Since there are 5 electrons in the third energy level, there are 5 valence electrons.
Hope that helps.
During ionic bonding, there must be a chemical interaction between...
O metallic elements, only
O nonmetallic elements, only
O one metallic and one nonmetallic element, only
O metalloids ,only
Helga has a box. She wants to determine how much the box can hold. Which measurement should she calculate?
A) Length
B) Area
C) Volume
D) Perimeter
C) volume
Explanation:
hope it helps !
Answer:
Volume. "How much the box can hold" means how much matter can fit into the box
Formula of a copper (II)sulfate hydrate lab
Mass of empty dish: 50.58 g
mass of crystals and dish: 55.63
mass of crystals after first heating: 54.57
mass of crystals after second heating: 53.83
mass of crystals after 3rd heating: 53.74
then it asks for the mass of crystals in the evaporating dish. i said 50.58/55.63x100= 90.94(i’ve yet to round to significant figures) and i’m unsure as to whether or not this is the proper equation?? i get more questions on the crystals for the heating, and then it goes to ask: determine the mass of water evaporated from ye crystals during the heating. If you know what equation to use, please let me know!!
the other questions: using the mass of water evaporated from the crystals after the 3rd heating, determine the percentage by mass of water in the copper (II) sulfate hydrate crystals.
Based on the following formulae fir copper determine the GFM of the hydrate crystals: CuSO4 x 5H2O
then more like that but this ones for the accepted percentage by mass of water in the hydrate crystals: CuSO4x5H2O.
then determine percent error.
Answer:
Weigh the empty crucible, and then weigh into it between 2 g and 3 g of hydrated copper(II) sulphate. Record all weighings accurate to the nearest 0.01 g.
Support the crucible securely in the pipe-clay triangle on the tripod over the Bunsen burner.
Heat the crucible and contents, gently at first, over a medium Bunsen flame, so that the water of crystallisation is driven off steadily. The blue colour of the hydrated compound should gradually fade to the greyish-white of anhydrous copper(II) sulfate. Avoid over-heating, which may cause further decomposition, and stop heating immediately if the colour starts to blacken. If over-heated, toxic or corrosive fumes may be evolved. A total heating time of about 10 minutes should be enough.
Allow the crucible and contents to cool. The tongs may be used to move the hot crucible from the hot pipe-clay triangle onto the heat resistant mat where it should cool more rapidly.
Re-weigh the crucible and contents once cold.
Calculation:
Calculate the molar masses of H2O and CuSO4 (Relative atomic masses: H=1, O=16, S=32, Cu=64)
Calculate the mass of water driven off, and the mass of anhydrous copper(II) sulfate formed in your experiment
Calculate the number of moles of anhydrous copper(II) sulfate formed
Calculate the number of moles of water driven off
Calculate how many moles of water would have been driven off if 1 mole of anhydrous copper(II) sulfate had been formed
Write down the formula for hydrated copper(II) sulfate.
#*#*SHOW FULLSCREEN*#*#
Explanation:
Hydrochloric acid (HCl) and sodium hydroxide (NaOH) react to form water and sodium chloride (NaCl). If you have 2.87 g of HCl, 3.75 g of water, and 1.98 g of NaCl, how many grams of NaOH were reacted? Your answer should go to the hundredths place.
Answer:
2.86g
Explanation:
Mass of HCl = 2.87g
Mass of water = 3.75g
Mass of NaCl = 1.98g
Unknown:
Mass of NaOH reacted = ?
Solution:
The reaction expression is given as:
HCl + NaOH → NaCl + H₂O
According to the law of conservation of mass, the mass of reactants and products must be the same.
Mass of HCl + Mass of NaOH = Mass of NaCl + Mass of H₂O
2.87g + Mass of NaOH = 1.98g + 3.75g
Mass of NaOH = 1.98g + 3.75g - 2.87g = 2.86g
Hydrogen and oxygen are examples of which of these?
elements
compounds
none of the above
molecules
I need to know astroides
Rearrange the elements in the order of increasing first ionization energy. Place the element symbol with the lowest first ionization energy at the top, and the element with the highest first ionization energy at the bottom. I Br F CI
Answer:
I,Br,Cl,F
Explanation:
ionization energy decreases the farther down an element is
Which of the following latitudes receive the most direct solar energy?
A latitudes near the north pole
B latitudes near the south pole
C latitudes near mountain ranges
D latitudes near the equator
Answer:
The answer to your question is D.
Explanation:
The latitudes near the equator receives the most direct solar energy.
Hope this helps :)
need help with physical changes
Answer:
I give u three in explanation
Explanation:
Crushing the can, stomping on the can, and squishing the can
Question 2 (Multiple Choice Worth 2 points)
(01.03 LC)
2
A student is trying to calculate the density of a can. He already knows the mass, but he needs to determine the volume as well. Which of the following formulas can be used to calculate
the volume of the can?
3
O V =
3
1
OVE Tran
3
OV=53
Ov=mrah
Answer:
[tex]\pi[/tex] r² x h
Explanation:
A can is cylindrical in nature. Using the formula of the volume of the can, we can find this unknown volume.
The volume of cylinder is given as:
Volume of a cylinder = Area x height
Volume of a cylinder = [tex]\pi[/tex] r² x h
Therefore density of the can;
Density = [tex]\frac{mass}{volume}[/tex]
Dry ice changes from a solid to a gas in a process known as A. Melting B. Freezing C.sublimation
Answer:
c
Explanation:
solid to gas directly
Calculate the molar mass for oxygen gas
For example, the atomic mass of an oxygen atom is 16.00 amu; that means the molar mass of an oxygen atom is 16.00 g/mol. Further, if you have 16.00 grams of oxygen atoms, you know from the definition of a mole that your sample contains 6.022 x 10^23 oxygen atoms.
What does the slope of a distance versus time graph represent?
Total time
Average time
Average distance
Speed
Answer:
Speed
Explanation:
Motion can be represented by a distance-time graph, which plots distance on the y-axis and time on the x-axis. The slope of a distance-time graph represents speed. The steeper the slope is, the faster the speed.
Hope this helps!:)
PLSS HELP! The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (4 points)
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
The answer is option A..
3. A 240 mL sample of argon gas at 270 K is cooled until the volume is 180 mL. What is the new temperature?
Answer:
202.5 K
Explanation:
PLeaseeeeeee ANSWERRR
Answer: looks like A
Explanation:
Which condition must exist in order for conduction to occur between two substances?
ОО
A ) The molecules of the substances must be touching.
B) Both substances must be the same temperature.
C) At least one substance must be a liquid
D) Most of the molecules must be slow moving.
Answer: B
Explanation:
Answer:
B. Both substances must be the same temperature.
Explanation:
Please Help! Thank You
Answer:
61.5 dry quarts = 67.72509L
Explanation:
According to kinetic theory, all matter is made up of small particles. The particles are constantly
moving
Diagram 1 shows how the particles may be arranged in a solid.
Diagram 1
(a)
One kilogram of a gas has a much larger volume than one kilogram of a solid
Use kinetic theory to explain why.
Enter your answer
Answer:
Explanation:
(a) there are strong forces (of attraction) between the particles in a solid
accept molecules / atoms for particles throughout
accept bonds for forces
1
(holding) the particles close together
particles in a solid are less spread out is insufficient
1
or
(holding) the particles in a fixed pattern / positions
but in a gas the forces between the particles are negligible
accept very small / zero for negligible
accept bonds for forces
1
so the particles spread out (to fill their container)
accept particles are not close together
gas particles are not in a fixed position is insufficient
One kilogram of a gas has a much larger volume than one kilogram of a solid. In kinetic theory particles in a solid are less spread out but in gas the force between the particles are negligible.
What is Kinetic Theory of matter ?The kinetic theory of matter states that all matter is made up of tiny particles which are constantly moving in a state of motion. All particles should posses energy.
Thus from above conclusion we can say that One kilogram of a gas has a much larger volume than one kilogram of a solid. In kinetic theory particles in a solid are less spread out but in gas the force between the particles are negligible.
Learn more about the Kinetic theory of matter here: https://brainly.com/question/1948317
#SPJ2
Help plzzzzz ASAP!!!!!!!!
1. NaF, Na₂S, Na₃P, Na₂O
2. MgF₂, MgS, Mg₃P₂, MgO
3. AlF₃, Al₂S₃, AlP, Al₂O₃
Further explanationGiven
Ionic charge
Required
The formula of binary ionic compounds
Solution
Ionic compounds consisting of cations (ions +) and anions (ions -)
Ionic compounds usually consist of metal cations and non-metal anions
Metal: cation, positively charged.
Nonmetal: negatively charged
The anion cation's charge is crossed
The ionic compounds :
1. NaF, Na₂S, Na₃P, Na₂O
2. MgF₂, MgS, Mg₃P₂, MgO
3. AlF₃, Al₂S₃, AlP, Al₂O₃
all organisms of the same species have the same traits true or false? explain
Answer: It would be true
Explanation: Individuals of the same species have the same inherited traits but different acquired traits, such as what they have learned and skills they have developed. Only these different acquired traits can cause differences in each individual's chances of survival and reproduction.
The organisms have a variation in their genes. Those orgasms that share the same common ancestors have similarities in their genetic code, same anatomy, and the same emanate features.
As the life on earth took place some 4.5 billion years ago and since which the many organisms that evolved may possess the same genetic makeup that lead them to their evolution. There still exists interspecific variation and some have differences due to the mode of adaptation. Hence the statement is false.Learn more about the organisms of the same species that have the same traits
brainly.com/question/12649119.
The total number of the elements above with 2 valence electron is ____.
Answer:
four elements
Explanation:
He = 1s²
Be = 1s² 2s²
C = 1s² 2s² 2p²
Mg = 1s² 2s² 2p⁶ 3s²
Si = 1s² 2s² 2p⁶ 3s² 3p²
Ca = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Valence electrons are those electrons which are present in outer most electronic shell.
He, Be, Mg, Ca these four elements have 2 valence electrons.
While Si and C have four valance electrons.
The total number of the elements above with 2 valence electron is four.
The electronic configurations of the elements are given:
He = 1s²
Be = 1s² 2s²
C = 1s² 2s² 2p²
Mg = 1s² 2s² 2p⁶ 3s²
Si = 1s² 2s² 2p⁶ 3s² 3p²
Ca = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Valence electrons are those electrons which are present in outer most electronic shell.
He, Be, Mg, Ca these four elements have 2 valence electrons.Learn more:
brainly.com/question/16089134
A 0.200 M NaOH solution was used to titrate a 18.25 mL HE
solution. The endpoint was reached after 31.20 mL of titrant
were added. Find the molar concentration of the original HF
solution.
Answer:
M₂ = 0.34 M
Explanation:
Given data:
Molarity of NaOH =M₁ = 0.200 M
Volume of HF =V₂= 18.25 mL
Volume of NaOH added = V₁ = 31.20 mL
Molarity of HF solution = M₂ = ?
Solution:
M₁V₁ = M₂V₂
by putting values,
0.200 M × 31.20 mL = M₂ × 18.25 mL
M₂ = 0.200 M × 31.20 mL / 18.25 mL
M₂ = 6.24 M.mL / 18.25 mL
M₂ = 0.34 M
Megan let her wagon outside what was raining and filled with water. When Megan tried to move the wagon that afternoon, she failed to budge the wagon. Why did Megan's wagon become hard to move?
Answer:
The rain filled the wagon with water meaning it gave the wagon more weight which made it hard to move.
Which is an example of chemical change?
Answer:
Burning, cooking, rusting and rotting are examples of chemical changes.What three consumers live in the epipelagic zone?
If more of a liquid evaporates,does that mean it has stronger intermolecular forces
Answer:
No
Explanation:
The stronger the intermolecular forces the molecules tend to stay in the liquid phase. Compounds with weak intermolecular forces are more volatile and more molecules overcome those forces to pass to the gas phase.
