Answer:
the oxidation number of hydrogen is +2, while oxygen is -2
How many levels are in the classification system?
A: 7
B: 2
C: 4
D: 6
Answer:
7
Explanation:
There are seven major levels of classification: Kingdom, Phylum, Class, Order, Family, Genus, and Species.
So, the answer is option A.
I need this like NOW
An area on the map where we might see strong winds is:
Question 5 options:
near Maine
near California
near Washington D.C.
near Kansas City
Which of the following is the best way to make a conclusion?
A. The experiment must be manipulated until the results show what you want
B. Estimate results to where they should be
C. Choosing the results you like
D. Comparing data from the experiment to the prediction of the hypothesis
What is the total pressure of a mixture of gases, with 23 atm, 10 atm, 16 atm, and 30 atm?
Many power plants produce energy by burning carbon-based fuels, which also produces carbon dioxide. Carbon dioxide is a greenhouse gas, so over-production can have negative effects on the environment. Use enthalpy of formation data to calculate the number of moles of CO2(g) produced per megajoule of heat released from the combustion of each fuel under standard conditions (1 atm and 25 °C).
Answer:
2.54 molMJ-1
Explanation:
The formation of CO2 is according to the equation;
C(s) + O2(g) -------> CO2
ΔHreaction = ΔHCO2 - [ΔHO2 + ΔHC]
ΔHO2 and ΔHC = 0 KJ
ΔHCO2 = -393.5 KJ
Hence;
ΔHreaction = -393.5 KJ - 0 KJ
ΔHreaction = -393.5 KJ
1 mol of CO2 yields -393.5 KJ/mol
The negative sign only means that heat was evolved in the process.
nCO2 = 1 mol CO2/393.5 KJ * 1 * 10^3 KJ/1MJ
nCO2 = 2.54 molMJ-1
PLZ HELP NO LINKS
What cell structure is necessary for photosynthesis?
xylem
chloroplasts
cell walls
roots
how would you measure out five moles of a gas?
Which part of the body transports molecules from food and air to the cells of the body
Answer:
Molecules from food and molecules of oxygen move from the mouth and the nose to cells of the body through a series of blood vessels, including veins, arteries, and microscopically small blood vessels (capillaries), that extend throughout the body.
Explanation: This is right
what is the first element in the periodic table?
Answer:
the first element on the table is Hydrogen
How many moles of titanium are in a sample containing 2.8 x 10^24 atoms?
1) 1.69 x 10^48
2) 4.65 x 10^43
3) 4.65
4) 0.0465
5) 48
Answer:
4.65 moles
Explanation:
To calculate this, we can use Avogradro's Number: 6.022*10^23
[tex]2.8*10^2^4*\frac{1mole}{6.022*10^2^3} =4.65mol[/tex]
So, there are 4.65 moles in 2.8*10^24 atoms of Ti
Fill in the missing information:
1. Complete Nuclear Symbol ________
2. Atomic # ________
3. Mass number ________
# Protons 22
# Electrons 18
# Neutrons 26
4. Charge _________
Answer: 1. Complete Nuclear Symbol : [tex]_{22}^{48}{Ti^{4+}}[/tex]
2. Atomic number : 22
3. Mass number : 48
4. Charge : 4 +
Explanation:
Atomic number is equal to the number of protons.
Mass number is the sum of number of neelectrons. utrons and number of protons.
Given : no of protons = 22 , thus atomic number = 22
Mass number = number of neutrons + number of protons
Mass number = 26 + 22 = 48
Also for a neutral atom , the number of protons is equal to the number of electrons. But here electrons are 4 less than protons, which means the atom has lost 4 electrons and thus will have a charge of 4+.
The atomic number is specific to an element, and the element with atomic number 22 is Titanium (Ti). The representation is [tex]_{22}^{48}{Ti^{4+}}[/tex]
Help please
Lunar eclipses happen when the _____.
moon passes between the Earth and the sun
Earth passes between the sun and the moon
sun passes between the Earth and the moon
Answer:
mook passes between the earth and sun
A 59.7 g piece of metal that had been submerged in boiling water was quickly transferred into 60.0 mL of water initially at 22.0 °C. The final temperature is 28.5 °C. Use these data to determine the specific heat of the metal. Use this result to identify the metal.
based on their scientific names, you know the cats felis catus and felis bieti do not belong to the same
A. family
B. species
C. zoo
D. domain
In an ecosystem, based on their scientific names, you know the cats felis catus and felis bieti do not belong to the same species.
What is an ecosystem?
Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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Experimental Data
Enter the data shown in the video for Unknown Sulfate #23 below or where required, calculate the value from your data:
Mass of empty 250-mL beaker (from video) =129.536g
Mass of 250-mL beaker and unknown sulfate (from video) =129.840g
Mass of unknown sulfate (calculated) =0.304g
Mass of empty crucible (from video) =10.320g
Mass of crucible and barium sulfate (from video) =10.723g
Mass of barium sulfate =0.403g
Calculations and Conclusions
Calculate the mass of sulfate in the unknown sample:
Mass of sulfate in unknown =_______g
Calculate the percentage by mass of sulfate in the unknown sample:
Mass percent of sulfate in unknown =
%
The cation in the unknown sulfate is one of the following:
Al3+ Na+ Ni2+ K+ NH4+ Cd2+
For each of these six cations, write the formula of its sulfate, and calculate the percentage mass of sulfate in the compound.
Formula of aluminum sulfate =
Mass percent of sulfate in aluminum sulfate =
%
Formula of sodium sulfate =
Mass percent of sulfate in sodium sulfate =
%
Formula of nickel(II) sulfate =
Mass percent of sulfate in nickel(II) sulfate =
%
Formula of potassium sulfate =
Mass percent of sulfate in potassium sulfate =
%
Formula of ammonium sulfate =
Mass percent of sulfate in ammonium sulfate =
%
Formula of cadmium sulfate =
Mass percentage of sulfate in cadmium sulfate =
Gallium (Ga, 69.723 g/mol) is a metalloid obtained from its salts during the smelting of ores of other elements, like Zinc, Ga has broad applicability in the electronics industry. It is also used as a safe replacement for mercury in thermometers as it melts at 29.8 oC and has a heat of fusion of 5.59 kJ/mol. What is the entropy change of of gallium in as it melts when placed on a surface at 29.8 oC?
Answer:
4.255 J/ K
Explanation:
Given data :
mass of Gallium = 16 gm
molar mass = 69.723 g/mol
hence no of moles = 16 / 69.723 = 0.23 moles --------- ( 1 )
Δh ( heat fusion ) = 5.59 KJ/mol
Temperature = 29.8°C = 302.8 k
Determine the entropy change of gallium
Δs ( entropy change ) = heat fusion / temperature
= ( 5.59 * 1000) J/mol / 302.8 = 18.46 J/k*mol
Hence entropy change of gallium
= Δs * no of Gallium moles
= 18.46 * 0.23 = 4.255 J/ K
Please please help me
Answer:
I agree with Omar because it depends on what the charge of the object and magnet is. If the magnet is negative and the object is positive, they will pull together. If the magnet is negative and the object is negative then they will pull apart.
Explanation:
The worst feeling is when you are hurting so badly inside but not a single tear comes out.
Anyone relate?
I know i can.
Answer:
chemistry wow
Explanation:
how many moles are 20 grams of Helium ?
Answer: The correct answer is 5.00 moles
Explanation:
Determine the number of atoms in 3.14 g gold
What is the concentration of kl solution if 20.68g of solute was added to enough water to form 100ml solution?
Answer:
1.25 M
Explanation:
Step 1: Given data
Mass of KI (solute): 20.68 g
Volume of the solution: 100 mL (0.100 L)
Step 2: Calculate the moles of solute
The molar mass of KI is 166.00 g/mol.
20.68 g × 1 mol/166.00 g = 0.1246 mol
Step 3: Calculate the molar concentration of KI
Molarity is equal to the moles of solute divided by the liters of solution.
M = 0.1246 mol/0.100 L= 1.25 M
heat is the movement from areas of ___ temperature to areas of ___ temperature
Answer:
heat is the movement from areas of high temperature to areas of low temperature
Which two substances are covalent compounds?
A. C6H12O6(s) and KI(s)
B. C6H1206(s) and HCl(g)
C. KI(S) and NaCl(s)
D. NaCl(s) and HCl(g)
Answer:
Option B is correct: C6H1206(s) and HCl(g)
Which do all cells need in order to function?
oxygen
water
carbon dioxide
offspring
Answer:
oxygen is the correct answer
Explanation:
you need oxygen in order to breath, eat, drink, and many other stuf! hope i helped!
When the following equation is balanced, what is the coefficient of oxygen?
C2H5OH() + O2(g) --> CO2(g) + H2O()
Answer:
The answer is 3
C2H5OH + O2 CO2 +H2O (unbalanced)
C2H5OH +3O2(g). 2CO2(g)+3H2O(balanced)
According to the balanced chemical equation, C₂H₅OH + 3 O₂[tex]\rightarrow[/tex] 2 CO₂ + 3 H₂O the coefficient of oxygen is three.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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Help!!
Which of the following tends to have increased solubility from increased pressure?
A gas in a liquid.
a liquid in a solid.
a solid in a gas.
A solid in a liquid.
Answer:
a solid in a gas
Explaination:
because soild will take a long while to dissolve into liquid by heating the soild with gas it will disslove quicker
HELP!
The law of conservation of energy states:
A. Energy increases exponentially with times
B. Total energy decreases due to energy output.
C. Energy cannot be created or destroyed.
D. Energy always remains in the same form.
Answer:
C
Explanation:
energy cannot be created or destroyed like solar energy for instance. it is already energy because it comes from the sun and for other reason.
Hope this helps!
How many moles of Ag can be obtained from 2.77 moles Cu using the following
balanced reaction?
2AgNO3
+ Cu
Cu(NO3)2
+ 2Ag
Answer:
2.77×2= 5.4 mol Ag can be obtained
Why is it important for some skateboarding ramps to be tall? Use the terms "potential energy" and "kinetic energy" in your answer. plsssssss help meeee Plzzz in kids words
Explanation:
Yw ❤
Shorter people have a lower center of gravity. Taller people have a higher center of gravity. A lot of skateboarding tricks depend on the center of gravity.
What is kinetic energy?
Kinetic energy is a form of energy it possess when any object or person is in motion . It can be defined as the work needed to be done to produce a motion in a object from rest position.
If we want to acceleration in an object then we must apply a force on a object to give motion so we can say that we required to do work for acceleration and then we can say that required is equal to kinetic energy.
Mathematically
Kinetic energy =1/2mv^2
Where
m = mass of object.
v = velocity of object
Kinetic energy is vector quantity it means that it have both i.e magnitude and vector.
S.I unit of Kinetic energy is Joule.
Therefore, Shorter people have a lower center of gravity. Taller people have a higher center of gravity. A lot of skateboarding tricks depend on the center of gravity.
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he image shows two air fronts moving in a region. The cold front is moving faster than the warm front.
Which will likely happen if the cold front continues to advance faster than the warm front?
Cold air will pass over the warm air, causing dry weather in the region.
Cold air will pass over the warm air, causing dry weather in the region.
Cold air will push up the warm air, resulting in heavy rainfall in the region.
Cold air will push up the warm air, resulting in heavy rainfall in the region.
Cold air will push up the warm a
Answer:
Cold air will push up the warm air, resulting in heavy rainfall in the region.