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
Which of the following would be a part of an environment engineer's job description ?
Answer:
where is the options
Explanation:
give options
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:
Jayden says that the dentist can shine a special light on his teeth that will make his teeth become whiter. Can light change Jayden’s teeth?
Answer:
No
Explanation:
This is because light cannot not whiten Jayden's teeth but light can change materials by hearing it up. There are some substances or tooth paste that can be use to whiten the teeth because of the content they are made off which whitens the teeth. Some of it include baking soda, hydrogen peroxide toothpaste, tumeric toothpaste, toothpaste that contain fluoride.
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:
Please helppppppppppppppppppp
50 ppoints
Answer:
I can’t see the whole page
Explanation:
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
i need a short paragraph (about two sentences) describing the geologic time scale.
The geologic time scale is the “calendar” for events in Earth history. It subdivides all time into named units of abstract time called—in descending order of duration—eons, eras, periods, epochs, and ages.
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)
Describe the distribution of mass within an atom
Answer:
The nuclei of most atoms also contain neutrons . The masses of subatomic particles are very tiny. ... Since the nucleus contains protons and neutrons, most of the mass of an atom is concentrated in its nucleus. Protons and electrons have electrical charges that are equal and opposite.
There are 2 places where charge is located in the atom:
the nucleus contains neutrons (zero charge) and protons (positive charge)
Around the nucleus there are electrons located on electron shields and the charge of electrons is equal to the charge of protons in the nucleus, but have negative sign.
To sum it all up we can say that the charge of protons in the nucleus is reduced by the charge of electrons on the orbits to make the atom electrically neutral.
which two statements correctly describe the theory of plate tectonices
Answer:
It explains how continents have shifted over time and It was developed based on data that scientists collected about the ocean floor.
I NEED HELP PLS PLS PLS
The products of a chemical reaction are chemically different substances than the reactants of a chemical reaction.
True or false?
this statement is true
Answer:
Hope it helps u
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)
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.
I can be formed into a sheet, I am high in luster, and am a very good conductor. I must be a ...
a
metal
b
nonmetal
c
metalloid
d
noble gas
Answer: metal
Explanation:
What is the atomic number of the following element??
Answer:
91
Explanation:
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
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
connect them please, dont guess ill give brainiest to the FIRST answer + 29 points
Answer:
I cant see it sorry
Explanation:
Post another one
Find the pH of a solution containing [H+]=0.00003
Answer:
Acid
Explanation:
because acid has a pH of6_1
what is on the left side ?
Answer:
reactants
Explanation:
Which of the following traits in inherited?
)piano skills
)strong muscles
)sun - bleached hair
)height
Sun-Bleached hair.
You can't exactly pass down piano skills, they have to be taught and also you can't just be born with strong muscles, they also have to develop over time. Height can't exactly be passed down because some parents are tall and their kids come out short. That leaves the only other option to be Sun-Bleached Hair (hair color).
Hope this helps and have a nice day.
-R3TR0 Z3R0
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:
How many mililiters are in 0.5000 liters?
Question 6 options:
50 ml
500 ml
0.5000 ml
5,000 ml
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.
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.
you want 200 mL of a 0.1 g/mL solution of sugar. how do you prepare the solution?
Form of energy knows as light energy
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].
4) How many atoms are present in a sample of oxygen, O2 with 12.222 moles?
Answer:
two oxygen atoms