the mass number of an element whose atoms contain 18 protons, 22 neutrons and 18 electrons
Answer:
Argon has the chemical formula Ar. Argon has 18 protons and 22 neutrons in its nucleus giving it an Atomic Number of 18 and an atomic mass of 40. Argon is a Noble Gas. Argon is a gas at room temperature.
Explanation:
Why were your results for the Southern Hemisphere opposite of what you found for
the Northern Hemisphere?
what is the oxidation number of oxygen in most compounds
Answer:
2-
Explanation:
Oxygen always act with an oxidation number of 2- unless we're talking of peroxide such as H2O2, where oxygen acts with an oxidation number of 1-
Helpppppppp plzzzzzz asaaaapppp
Answer:
Alright, the first thing we have to do is to balance the chemical equation
2Na3N -----> 6Na + 1N2
We have 60g of Na3N, we convert them into moles by dividing the mass of the compound by the molar mass.
Molar mass of Na3N = (22.98 x 3) + (14) = 82.94g/mol
60 = 0.72341451651 moles of Na3N
82.94
Now because we did the balanced equation, we know the mole to mole ratio of Na3N to N2 would be 2:1, so in order to get the moles of N2 you have to divide the moles of Na3N by 2
0.72341451651 moles/2 = 0.361707258 moles of N2
Now that we have the moles of N2, we just have to determine the mass of it in grams. In order to do that, just multiply the moles by the molar mass of N2 (28g/mol)
0.361707258 x 28 = 10.13g of N2
Therefore the decomposition of 60g of Na3N would result in 10.13g of N2 (nitrogen gas)
Choose one metal from the reactivity series that will react safely with dilute sulphuric acid
Please can someone answer quickly
Answer:
Zinc (Zn) will safely react with dilute sulphuric acid.
Explanation:
If correct please give brainliest
Stay safe and healthy
Thank You
Particulate Electrical Forces Unit Test for Connexus, Chemistry A
I've already finished the questions, but im stuck on the written parts 16-18, can anyone give a hand? :(
I’m sorry no one helped you with those questions. But could you please be a doll and give me the answer for the multiple-choice questions 1-15. Pleaseee I’m so desperate.?
Please Help giving high points. Perform the following mathematical operation, and eport the answer to the correct number of significant figures. 4568/1.3 = [?]
Answer:
1.3 is the value with the lowest sig figs in your question. So we have 2 sig figs.
4568/1.3 = 3513.84615
Now let's change the answer in sig figs.
We know that trailing zeros don't actually count as part of sig figs.
So we can round the answer to 3500, having the 2 sig figs (3 and 5) while the trailing zeros don't count.
Final answer = 3500
Choose all of the examples that show a chemical change.
A) A woodpecker digs in the bark.
B) A dead tree rots on the ground.
C) A forest fire burns a lot of trees.
D) A farmer is cutting logs with an axe.
E) A tree drops rainwater from its leaves.
Answer:
B and C
Explanation:
Answer:
B) A dead tree rots on the ground.
C) A forest fire burns a lot of trees.
Explanation:
It cannot return the the state it was in before or have the same composition it had before.
A teacher places a cup of coffee onto an electronic balance at the front of the science laboratory. The teacher then adds three large teaspoons of sugar to the coffee. The volume of the coffee does not appear to increase. What happens to the mass displayed on the front of the balance?
Answer:
it will be same as before
Answer:
The mass on the balance stays the same
Explanation:
.
PLEASE HELP ME I NEED HELP
Answer:
5 moles S x (36.02 g S/mole S) = 180.1 grams of S
Explanation:
The periodic table has mass units for every element that can be correlated with the number of atoms of that element. The relationship is known as Avogadro's Number. This number, 6.02x[tex]10^{23}[/tex] , is nicknamed the mole, which scientists found to be a lot more catchy, and easier to write than 6.02x[tex]10^{23}[/tex]. The mole is correlated to the atomic mass of that element. The atomic mass of sulfur, S, is 36.02 AMU, atomic mass units. But it can also be read as 36.02 grams/mole.
This means that 36.02 grams of S contains 1 mole (6.02x[tex]10^{23}[/tex]) of S atoms.
This relationship holds for all the elements. Zinc, Zn, has an atomic mass of 65.38 AMU, so it has a "molar mass" of 65.38 grams/mole. ^5.38 grams of Zn contains 1 mole of Zn atoms.
And so on.
5.0 moles of Sulfur would therefore contain:
(5.0 moles S)*(36.02 grams/mole S) = 180.1 grams of S
Note how the units cancel to leaves just grams. The units are extremely helpful in mole calculations to insure the correct mathematical operation is done. To find the number of moles in 70 g of S, for example, we would write:
(70g S)/(36.02 grams S/mole S) = 1.94 moles of S. [Note how the units cancel to leave just moles]
What is one element that is not found in the human body, air, or the universe? Brainliest to whoever gets it right! PLEASE HELP! :) 20 points for the question also! :D
Answer:
Technetium. It is only found in the stars.
Explanation:
Sorry, but thats all I could find for tou
The are many elements which are not present in human body. But almost all the discovered elements are there in the universe. But the one which is not present in earth and air is technetium
What is an technetium ?Technetium is the first synthesized element by man in 1937. Technetium has no stable isotopes and it is not found in earth. But it is present in stars. However, rare earth elements such as promethium , francium etc. can be prepared or observed from uranium ores.
There are many elements especially some actinides and lanthanides which are not present in earth naturally existence on starts and other planets.
Human body is made of various elements including carbon, oxygen, nitrogen, various metals like iron, zinc etc. Various enzymes contains different elements but the number of elements which are in the surroundings of human and not inside is larger.
Therefore, all the discovered elements are found in the universe and some them are not present in earth.
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Here's the question ~
Heat treatment of muscular pain involves radiation of wavelength of about 900 nm (nm = 10-⁹ m). which spectral line of H - atom is suitable for this purpose ?
[ RH = 1 × 10⁵ cm-¹ ]
[ h = 6.6 × 10-³⁴ Js ]
[ c = 3 × 10⁸ m/s ]
Thanks for Answering !
Using the Rydberg formula, the spectral line of H - atom is suitable for this purpose is Paschen, ∞ → 3.
Using the Rydberg formula;1/λ = RH(1/nf^2 - 1/ni^2)
Given that;
λ = wavelength
RH = Rydberg constant
nf = final state
ni = initial state
When final state = 3 and initial state = ∞Then;
1/λ = 1 × 10^7 m-1 (1/3^2 - 1/ ∞^2)
1/λ = 1 × 10^7 m-1 (1/3^2 )
λ = 900 nm
Hence, the correct answer is Paschen, ∞ → 3
Learn more about the Rydberg formula; https://brainly.com/question/17753747
If two atoms have very different electronegativities, will this for me ionic bond or a covalent bond
Answer:
It will be a covalent bond.
Explanation:
When two atoms combine, the difference between their electronegativities is an indication of the type of bond that will form. If the difference between the electronegativities of the two atoms is small, neither atom can take the shared electrons completely away from the other atom and the bond will be covalent.
how many molecules of atp are produced as a result of glycolysis
Answer:
2 ATP molecules are produced
Answer:
2 ATP molecules of ATP are produced
It takes 25 mL of 0.20 M of hydrochloric acid (HCI) to neutralize 50 mL of
sodium hydroxide (NaOH). What is the concentration of sodium
hydroxide?
Answer:
0.1 M
Explanation:
(25 mL) (0.20 M) / 50 mL = 0.1 M
why do i have white spots on my teeth after brushing?
Give an example for the neutralisation between a strong acid and a weak base, also mention the nature of its salt.
need help !! ~~~~
Answer:
Neutralization occurs when a strong acid and a strong base come together in a chemical reaction to form water and salt.
Explanation:
not sure huhuhu
A quantity of gas has a volume of 250L at 40°C. If the gas is heated to 120°C, what will the new volume be? Which law describes this change?
Answer:
706 L
Explanation:
P1V1 = P2 V2 3 atm 250.0 mL = 1 atm X
T1 T2 290 K 273 K
706 mL = X
how much percent of water should we add to sea water to change concentration from 3 to 2
Answer:
10 kg of water was added to the 20 kg of seawater to dilute it from 3% to 2%. Hope this helps!!!!!!
What is the atomic number of an atom?
Question 3 options:
the number of protons
the number protons and neutrons
the number of neutrons
the number of electrons and neutrons
Answer: The number of protons
Explanation:
-
Which image shows in nonrenewable resource?
Answer:
1
Explanatio
right on edge
Among the given images, the one which is an example of non-renewable source of energy is image -1 the cooking gas is a petroleum product and it is non-renewable.
What are non-renewable energy sources?Non-renewable energy sources are sources of energy that come from finite resources that cannot be replenished on a human timescale. They are called non-renewable because their reserves are being depleted faster than they can be replenished. These energy sources include:
Fossil fuels: Coal, oil, and natural gas are the three main types of fossil fuels. They are formed over millions of years from the remains of plants and animals that lived long ago. Fossil fuels are currently the most widely used sources of energy for electricity generation, transportation, and industrial processes.
Nuclear energy: Nuclear energy is produced through the process of nuclear fission, which involves splitting atoms of uranium or plutonium to release energy. Nuclear power plants generate electricity using this process.
Non-renewable energy sources are a major contributor to greenhouse gas emissions, which contribute to climate change. As a result, there is a growing need to transition to renewable energy sources that are sustainable and have a lower environmental impact.
Here, image 1 - cooking gas is non-renewable.
Find more on non-renewable sources:
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Help please I don’t know what to do
What is the problem with this chemical equation: H2 + O2 → H2O
Answer:
To make H2O, you need two H and one O. in this equation, you are given two Os which is too many. you'll end up with an extra O. H2 + O2 -> H2O + O
Lead has an atomic number of 82. Which statement describes all neutral atoms and ions of lead?
Neutral atoms of lead must have 82 electrons. Ions must have 82 electrons, as well.
Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer.
Neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
Neutral atoms of lead must have 82 protons, but ions can have more or fewer.
The neutral atom of lead must have 82 protons while ions can have b or less than 82.
The atomic number of an element is the number of protons in the nucleus of the element.
Also, for neutral atoms, the number of protons equals the number of electrons.
In ionic form, the number of protons/electrons of an atom may vary and be different from that of the neutral form.
Positive charges mean that the ion has less proton than its neutral version while negative charges mean that it has more electrons than its neutral version.
Thus, the neutral atom of lead will contain an equal number of protons as the electrons while its ionic form can have more or less than 82 protons.
More on atoms can be found here: https://brainly.com/question/803445?referrer=searchResults
how did Alexander dye ?
Answer:
After surviving battle after fierce battle, Alexander the Great died in June 323 B.C. at age 32. Some historians say Alexander died of malaria or other natural causes; others believe he was poisoned. Either way, he never named a successor.
Answer:
After surviving battle after fierce battle, Alexander the Great died in June 323 B.C. at age 32. Some historians say Alexander died of malaria or other natural causes; others believe he was poisoned. Either way, he never named a successor
Explanation:
hope it helps
The process in which the nucleus of an atom splits into two lighter atoms, releasing a large amount of energy, is nuclear ______ Fusion Fission Radiation Energy.
Answer:
B. Fission
Explanation:
On edge
When a magnesium is heated, it burns in air with a dazzling white flame to form a white powder .What it called?
Balanced Equation –
[tex]\purple{\bf{2Mg + O_2 = 2MgO}}[/tex]
Physical states –
Magnesium → Mg ( In Solid State) Oxygen → [tex]\sf{O_2}[/tex] ( Gaseous State) Magnesium Oxide → MgO ( In Solid State Or White powder)_______________________________________
It is magnesium Oxide MgO2
Describe the S-wave shadow effect of earth quakes.
Answer: The shadow zone is the area of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves. The shadow zone results from S waves being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.
Explanation: 104 to 140 degrees from a given earthquake
What is produced when you react a metal with oxygen?
2. How many MOLES of cobalt(III) sulfate are present in 4.25 grams of this compound?
moles.
Answer:
1 grams Cobalt(II) Sulfate = 0.006451787725861 mole using the molecular weight calculator and the molar mass of CoSO4.
Explanation: