Answer:
Chemical properties of each elements are determined as the elements of the electronic configuration and particularly by its outermost valence electrons in addition the total number of electron shells an atom determines to which period it belongs to .
maybe this might help u
What is the molecular formula for a compound with an empirical formula of C₅H₄ and a molar mass of 128.16g?
Answer:
[tex]C_{10} H_{8}[/tex]
Explanation:
Molecular formula can be calculated by finding the ratio of the molecular molar mass to the empirical molar mass, then multiplying the subscripts of the empirical molar mass by that ratio.
The empirical molar mass is 5(12.01) + 4(1.01) = 64.09g
The molecular molar mass is 128.16g
128.16/64.09 = 2
So the molecular formula is [tex]C_{10} H_{8}[/tex]
A gas has a solubility of 1.46 g L at 8.00 atm of pressure. What is the pressure of a sample of the same gas that
contains 2.7 g/L of the dissolved gas?
Answer:
[tex]14.8\ \text{atm}[/tex]
Explanation:
[tex]C_1[/tex] = Initial concentration = 1.46 g/L
[tex]C_2[/tex] = Final concentration = 2.7 g/L
[tex]P_1[/tex] = Initial pressure = 8 atm
[tex]P_2[/tex] = Final pressure
From Henry's law we have the relation
[tex]\dfrac{C_2}{C_1}=\dfrac{P_2}{P_1}\\\Rightarrow P_2=\dfrac{C_2}{C_1}P_1\\\Rightarrow P_2=\dfrac{2.7}{1.46}\times 8\\\Rightarrow P_2=14.8\ \text{atm}[/tex]
The pressure of a sample of the same gas at the required concentration is [tex]14.8\ \text{atm}[/tex].
Calculate heat energy
Answer:
The equation for calculating heat energy is q=mCpΔT, where q is the heat variable, m is the mass of the object, Cp is the specific heat constant and ΔT is the temperature change.
Explanation:
Lead (II) chromate, PbCrO4, was used as a pigment in paints. How many atoms are in 25 g?
Answer:
4.658 * 10^22 atoms
Explanation:
Mass = 25 g
Number of atoms = ?
Number of moles = Mass / Molar mass
Molar mass of PbCrO4 = 323.1937 g/mol
Number of moles = 25 g / 323.1937 g/mol
Number of moles = 0.077352993 moles
1 mol = 6.022 * 10^23 atoms
0.077352993 mol = x
Solving for x;
x = 0.077352993 * 6.022 * 10^23 / 1
x = 4.658 * 10^22 atoms
HELPPPP!!! I need the CORRRECT answer
1.Which pair of properties describes the elements in Group 18?
a) They are gasseous at room tempature and chemically stable
b) they have 8 valence electrons and are stable
c) they are chemically stable and liquid at room tempature
d) they are magnetic and boil at room tempature
Answer: c
Explanation:
SnSe2
GaAs
Pb(SO4)2
Be(HCO3)2
Mn2(SO3)3
Al(CN)
i need to find their names
Answer:
Explanation:
SnSe2 = Tin (IV) selenide
GaAs = Gallium arsenide
Pb(SO4)2 = Lead(II) sulfate
Be(HCO3)2 =Beryllium Bicarbonate.
Mn2(SO3)3 = Manganese(III) Sulfite.
Al(CN)3 =Aluminum Cyanide
hope it helps :)
The equation below shows the decomposition of lead nitrate. How many molecules of PbO are produced when 11.5 g NO2 is formed?
2Pb(NO3 )2 (s) → 2PbO(s) + 4NO2 (g) + O2 (g)
What is the atomic number of the following element??
Answer:
91
Explanation:
Uranium has an atomic number of 92. How many neutrons does U-238 have?
Answer:
146 neutrons.
Explanation:
What is the bond angle in carbon dioxide, CO2?
connect them, dont guess please + 23 points
Answer:
Astronaut- highly trained individual for space travel
Payload Specialist- partnering scientist, journalist, or political guest.
Space Sickness- nausea, vomiting, and upset stomach.
Muscle Atrophy- the result of microgravity.
Johnson Space Center- training facility for U.S. astronauts.
A compound is made of 49.31% C, 43.79% 0 and the rest hydrogen. The molar
mass is 146.1g/mol, what are the empirical and molecular formulas?
(Show work)
Explanation:
49.31 + 43.79 = 93.10
finding the percentage of hydrogen in the compound hence 100-93.10 =6.9
therefore 6.9 percent of hydrogen is present in the compound
assuming that the compound is in 100 g so the elements present would be 49.31g of C , 43.79g of O and 6.9g of H
no. of moles of C = given mass÷molar mass
= 49.31 ÷ 12
=4.11 mol
no of moles of O = givem mass ÷molar mass
=43.79÷ 16
=2.73 mol
no. of moles of H =6.9÷1
=6.9 mol
dividing the no. of moles of each element by the least count of the elemnt to get the ratio of the simple whole numbr
therefore
so by dividing we get 1:1:2 of C:O:H
the empirical formula is CH2O
empirical formula mass of CH2O IS
= (12)+(2×1)+(16)
= 12+2+16
=30 G/MOL
n= molar mass of the compound ÷ empirical formula mass of the compound
so, n= 146.1 ÷30
n=5
molecular formula = n×empirical formula
molecular formula= 5×CH2O
molecular formula=C5H10O5 (ribose is the compound)
(they don't have science so I guess cemastry will do.)
warm air rises because of___
A student holds the back of his hand near an iron tosee if it's hot. The heat transfer is___
Warm water moves throuout a mattress because of___
In a swimmming pool The watter near the surface is warmer because of___
(i'll do the rest later)
warm air rises because of convection.
A student holds the back of his hand near an iron to see if it's hot. The heat transfer is conduction.
Warm water moves throughout a mattress because of ... why is there warm water in a mattress again? Convection, I guess.
In a swimming pool, the water near the surface is warmer because of convection and solar radiation; it's closer to the Sun than the bottom of the pool, so it receives more thermal radiation, making it warmer.
Item 3
Which statement describes the electrical conductivity of metals and semiconductors? Choose the correct answer.
Metals are poor conductors at low temperatures.
The conductivity of metals changes with changing pressure.
The conductivity of semiconductors changes with changing pressure.
Semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.
Answer:
Semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.
Explanation:
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
The statement which best describes the electrical conductivity of metals and semiconductors is that semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.
This ultimately implies that, semiconductors are typically an insulator (poor conductor) at low temperatures and a good conductor at high temperatures.
Additionally, conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
Which of the following is considered parasitism?
a
A hummingbird pollinating a flower.
b
A flea is sucking the blood from a dog.
c
A spider builds its web in a tree.
d
A bug hitches a ride on your backpack during a hike.
An advantage of cooking in steam is .
A. it is faster than boiling when pressure is added
B. foods are more flavorful
C. foods are more nutritious
D. All of the above.
Answer:
The answe is all of the above
Exactly 10.0 L of air -25°C is heated to 100.0°C. What is the new volume if the pressure is kept constant?
Answer: V2= 15.0403226 Liters
Explanation:
Use V1/T1=V2/T2
Make sure you change the degrees Celsius to Kelvin. (Kelvin = degrees Celsius +273)
10.0L / 248 K = V2/ 373 K
Cross multiply V1 and T2 and divide by T1
(10.0 L)( 373K)/ 248 K = V2
V2= 15.0403226 Liters (Kelvin cancels out)
a container of gas has a pressure of 1.45 atm at a temperature of 52 degrees celsius, if the pressure increases to 4.2 atm what would be the final temperature of the volume is held constant?
Answer:
941 K (668°C)
Explanation:
We have the following data:
Initial pressure : P1 = 1.45 atm
Initial temperature: T1 = 52°C + 273 = 325 K
Final pressure: P2 = 4.2 atm
Final temperature: T2 = ?
The relation between pressure and temperature for a gas at constant volume is given by Gay-Lussac's law:
P1/T1 = P2/T2
That means that the pressure is directly proportional to the absolute temperature (in K). So, we calculate T2 from the equation:
T2 = P2 x T1/P1 = 4.2 atm x (325 K/1.45 atm) = 941 K
Therefore, the final temperature would be 941 K (668°C). This is consistent with the law, that states that if the pressure increase, the temperature will be increased.
Which of the following statements is true? Running an electric current through a magnet can create a magnetic field, Electrons are found in the nucleus of an atom, The strength of a magnetic field increases with distance, Electric engines change electricity into magnestism
Answer:
running an electric current through a magnet can create a magnetic field
A car is driven for 3 hours. What else do you need to know to describe this car's speed?
the number of passengers in the car. the time of day.
the road the car in driven on.
the distance the car is driven.
Answer: Distance the car has driven
Explanation:
The speed equation is speed=distance/time and since we already know time we need to know distance to solve for speed
What type of decay does Am-241 undergo to become Np-237?
a. Alpha decay
c. Positron emission
b. Beta decay
d. Electron capture
The type of decay that Am-241 undergoes to become Np-237 is alpha decay. The correct option is a.
What is alpha decay?Alpha decay is a type of decay or transformation in which a nucleus emits an alpha particle and change into different atomic nuclei. The atomic number reduces by 2 and the mass is reduced by 4.
Am-241 is an isotope of the chemical element americium. It is a radioactive element and its radioactive decay period is 432.2 years. It is used in the testing of machinery.
When the nucleus of Am changes or emits a radioactive particle. It converts into Np-237. The process is called alpha decay. The atomic mass is reduced by four, and the 241 converts into 237, which become neptunium.
Thus, the correct option is a. Alpha decay.
To learn more about alpha decay, refer to the link:
https://brainly.com/question/27870937
#SPJ2
C7H6O2 + O2 → CO2 + H2O
can someone show me step by step how do balance that
Answer:
2C7H6O2 + 15O2 → 14CO2 + 6H2O
Explanation:
C7H6O2 + O2 → CO2 + H2O
Carbon is not balanced (Reactant - 7, Product - 1)
Adding 7 to CO2;
C7H6O2 + O2 → 7 CO2 + H2O
Carbon is now balanced, however hydrogen is not balanced (Reactant - 6, Product - 3)
Adding 3 to H2O;
C7H6O2 + O2 → 7 CO2 + 3 H2O
Hydrogen is now balanced, however oxygen is not balanced (Reactant - 4, Product - 3)
Since 3H2O gives an odd value of O, multiply all through by 2;
2C7H6O2 + 2O2 → 14 CO2 + 6 H2O
Oxygen is still not balanced (Reactant - 8, Product - 34)
Change 2O2 to 15O2;
2C7H6O2 + 15O2 → 14CO2 + 6H2O
Equation is now balanced.
Form of energy knows as light energy
What is the meaning of the acceleration value 9.8 m/s?????
Answer:
The value 9.8 m/s^2 is the average acceleration of a falling object due to the force of gravity on Earth. The letter g represents this value the formula v=gt. With this constant and formula, the speed of an object is calculated at the time t in seconds after it is dropped.
All objects fall at the same rate of speed due to gravity, regardless of their weight. If a small grain of sand and a bowling ball are dropped at the same time, both hit the floor at the same time. The value of g varies by one's location on the planet, ranging from 9.782 m/s^2 in the Panama Canal Zone to 9.832 m/s^2 at the Noth Pole
Explanation:
pls help need it now as I don't know the answer
Answer:
Iron :)))))))))))))))))))))))))
Answer:
The answer is Copper
Explanation:
Dalton's contribution was different from thatof the ancient Greeks who populated the existence of atoms.Point out the difference between the two ideas.
Answer:
See explanation
Explanation:
The Greeks held the belief that atoms where spherical. However, they thought that atoms of elements where different for the different states of mater. Dalton brought about the idea that the atoms of the same element are exactly alike irrespective of the physical state of the system.
Dalton introduced the idea that chemical reactions result from rearrangement of atoms in molecules. This idea was not captured by the early Greeks.
1) What is the mass in grams of a 51.2-mole sample of calcium?
Answer:
2051.9936 g
Explanation:
Mass = ?
Number of moles = 51.2 mol
The relationship between both quantities is given by the equation;
Number of moles = Mass / Molar mass
Solving for mass;
Mass = Number of moles * Molar mass
Mass = 51.2 * 40.078
Mass = 2051.9936 g
New evidence can cause scientists to revise a scientific theory. If new evidence comes to
light, which is most likely to happen?
Answer: after years of research if the evidence still supports a change the theory will be revised
Explanation:
I think that’s it
What equation is used to calculate the pH of a solution?
Answer:
pH = -log[H3O+] or pH = -log[H+]
Explanation:
pH is the negative log of hydronium concentration or hydrogen ion concentration. The two are essentially interchangeable.
Find the pH of a solution containing [H+]=0.00003
Answer:
Acid
Explanation:
because acid has a pH of6_1