If I could change something in my previous science classes, it would have been the fact that I struggled in the question concerning exponents. It was simple one, but I don't know how I didn't understood that. For example, if there is a question with a calculation "xy²", then I would first multiply x and y, and then calculate the exponent. I did 3 of the questions wrong because of this, it was when I was in 7th grade. I wish I had not done this kind of silly mistake. I an in 10th grade and understand it well now, though.
How does the chemistry of the ocean change in response to high levels of CO2 in the atmosphere?
1s 2s22p63s23p4
How many valence electrons does this atom have?
2
6
4
12
Answer:
6
Explanation:
How many valence electrons does this atom have?
answer 6
Answer:
6.
Sulphur has 6 valence electrons.
( .°. that's the electronic configuration of sulphur .)
If the hydrogen ion concentration, (H+), in a solution is 5.39 x 10-8 M,
what is [OH-]?
A.1.86 x 1021 M
B. 1.86 x 10-7 M
Answer: 1.86*10^-7M
Explanation:
Answer:
B. 1.86 x 10^-7 M
Explanation:
Which of the following apply to organic compounds. Select all that apply. Organic compounds cannot be synthesized. Organic compounds contain carbon. All organic compounds are products of living things. Organic compounds can be synthesized. All compounds that contain carbon are organic.
Answer:
Organic Compounds CAN BE synthesized
Organic Compounds contain Carbon
I NEED HELP ASAP!!!
All of the following are examples of ways to increase mechanical advantage EXCEPT:
Select one:
a.adding more threads to a screw
b.making a wheel larger than an axle
c.increasing the length of a ramp
d.increase the steepness of a ramp
Which of the following would be most likely to form a +2 cation?
The Periodic Table
A. Sulfur (S)
B. Calcium (Ca)
C. Chlorine (CI)
O D. Potassium (K)
Calcium because group 2 metals are all 2+ cations
Solids have_____
density and_____
compressibility compared to
liquids.
Answer:
higher density and lower compressibility
I need help please!!!!!
Answer:
sorry..,...........
.....
PLS HELP!! WILL MARK BRAINLIEST! 99 POINTS!
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
Did you know that before pencil erasers were added on in 1858. people got rid of pencil markings
with white breadcrumbs? Which would erase pencil markings better, an eraser or white bread
crumbs?
Make a hyphotesis plz
Answer:
I guess eraser is better than bread crumbs
Erasers would be better than white bread or crumbs to erase the pencil marks because they would not leave any food marks on the paper and using bread crumbs.
What is an eraser?An eraser is an object of stationary which is used to remove pencil marks from the paper. It is used during writing, when we write something wrong, we could erase or remove the writing from the paper. It is very useful for small children because they usually make mistakes while studying.
Erasers are made from the milk of rubber plants. The milk is collected from the plants, and then it is mixed with chemicals and set down, and then cut into pieces.
Thus, Erasers would be preferable to utilizing bread crumbs or white bread because they would not leave any food stains on the paper after erasing the pencil markings.
To learn more about eraser, refer to the link:
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How much does 9.8 liters of ammonia (NH3) weigh at standard temperature and pressure (273 K and 100 kPa)?
A. 13.84 grams
B. 7.44 grams
C. 17 grams
D. 12.91 grams
Reset Selection
what is element Na in a periodic table
Answer:
Sodium.
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is ²³Na.
Answer:
sodium
atomic mass 22.99
atomic number 11
period 3 group 1 1a
sodium is also an Alkali metal
Explanation:
I have a periodic table on my computer I hope I helped
Determine the grams of sodium chloride produced when 10 g of sodium react with 10 grams chlorine gas according to the equation 2Na + Cl2 = 2 NaCl
Answer:
16 g
Explanation:
Step 1: Write the balanced equation
2 Na + Cl₂ ⇒ 2 NaCl
Step 2: Identify the limiting reactant
The theoretical mass ratio (TMR) of Na to Cl₂ is 46:71 = 0.65:1.
The experimental mass ratio (EMR) of Na to Cl₂ is 10:10 = 1:1.
Since EMR > TMR, Cl₂ is the limiting reactant
Step 3: Calculate the mass of NaCl produced
The theoretical mass ratio of Cl₂ to NaCl is 71:117.
10 g Cl₂ × 117 g NaCl/71 g Cl₂ = 16 g NaCl
Identify an element as a metal or a non-metal according to its position in the Periodic
Table
Answer:
Metals on the left of the Periodic Table.
Non-Metals on the top-right, plus Hydrogen.
Es la representación escrita de un cambio químico, se construye con simbología, la cual fue establecida para una mejor interpretación universal de las reacciones.
Can someone plz help me :<
Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens
Explanation:
Which medicines are including Chemicals?
Can you help Please!
Answer:
Compounds used as medicines are most often organic compounds, which are often divided into the broad classes of small organic molecules (e.g., atorvastatin, fluticasone, clopidogrel) and "biologics" (infliximab, erythropoietin, insulin glargine), the latter of which are most often medicinal preparations of proteins
Write an equation to show how perchloric acid, HClO4, reacts with water. Include states of matter in your answer.
Since perchloric acid is a strong acid, it will dissociate completely, along with water. The products will be Perchlorate ions and Hydronium ions after the Perchloric acid gave away its proton and water, acting as a base, accepted that abandoned proton.
Write a hypothesis that answers the lesson
question, "While observing a chemical reaction,
how can you tell which reactant is limiting?"
Hypothesis: If a substance is the limiting
reactant, then..
Answer:
the reaction will come to a halt and the other reactant will still be present.
A reaction happens quickest during:
A. The beginning of the reaction
B. It is constant throughout the reaction
C. The end of the reaction
D. The middle of the reaction
The reaction is the formation of the product from the reactants. A reaction happens quickest during the beginning of the reaction. Thus, option A is correct.
What are the factors affecting the reaction rate?The reaction rate is the pace at which the reaction takes place and the breakdown or the combination of the reactants to produce the products. The rate of reaction depends on the concentration of the reactants.
The concentration of the reactants is in direct proportion with the rate as at the beginning of a reaction there is a higher amount of substance present than at the end.
As the reaction proceeds, the reactants get consumed and their concentration decreases. As there is a decrease in concentration the rate of the reaction converting and producing the products also decreases.
Therefore, option. the rate of reaction is fast at the beginning.
Learn more about reaction rate here:
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write the balanced chemical equation for the following word equation. sodium+sulphate Acidsodium sulphate +hydrogen
Answer:
2NaOH+ H2SO4 → Na2SO4 + 2H2O
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
Answer:
Sodium+sulphate=Na2SO4
Acidsodium sulphate + hydrogen=Na2SO4+H2O
A spontaneous reaction occurs when the sign of free energy is
A: Neutral
B: Zero
C: Positive
D: Negative
solution is an example of______mixtures
Answer:
homogeneous mixture must be the answer
PLEASE HELP URGENT!!
What is the SI system? What are its benefits?
Answer:
The SI system : The international system of units.
It is a scientific method of expressing the magnitudes or quantities of important natural phenomena.
Benefits of SI system
It is a coherent system of units ( a system based on certain sets of fundamental units )It is a rational system of units ( it assigns only one unit to a particular physical quantity )What is the volume of 3.6g of material with a density of 13.2g/mL? Include units and go to 4 decimal places.
Answer:
0.2727 mL
Explanation:
use density to convert mass to volume
3.6 g x 1 mL = 0.2727 mL
13.2 g
3. An atom
OF
elemente A has mass number 39 and 19 protons
Write the electron arrangement of the atom
Answer:
Explanation:
Potassium (K) atom has 19 electrons. The full electron configuration of Potassium (K) is 1s22s22p63s23p64s1
Principal energy level
Quantum number: n
1
2
3
4
5
6
Sublevels
availableQuantum number: l
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f 5g
6s 6p 6d 6f 6g 6h
Determine the empirical formula for compounds that have the following analyses. a. 28.4% copper, 71.6% bromine b. 39.0% potassium, 12.0% carbon, 1.01% hydrogen, and 47.9% oxygen c. 77.3% silver, 7.4% phosphorus, 15.3% oxygen d. 0.57% hydrogen, 72.1% iodine, 27.3% oxygen
Answer:
See explanation
Explanation:
Cu- 28.4/63.5, Br- 71.6/80
Cu- 0.447/0.447, Br- 0.895/0.447
Cu- 1, Br - 2
Empirical formula = CuBr2
b)
K- 39.0/39, C-12.0/12, H- 1.01/1, O- 47.9/16
K= 1, C-1, H- 1. O-3
Empirical formula= KHCO3
c)
Ag- 77.3/108, P-7.4/31, O-15.3/16
Ag-0.716/0.239, P- 0.239/0.239, O-0.956/0.239
Ag-3, P-1, O-4
Empirical formula= Ag3PO4
d)
H-0.57/1, I- 72.1/127, O-27.3/16
H- 0.57/0.57, I- 0.57/0.57, O-1.71/0.57
H-1, I-1, O- 3
Empirical formula= HIO3
a. The atomic mass defines the elemental identity of an atom. b. The atomic number of an element is approximately equal to the number of protons in an atom of that element. c. Helium is the smallest atom and has an atomic number of 1. d. Isotopes of the same element have the same atomic mass.
B
Explanation:
option b is correct because
hydrogen is smallest atom
isotopes of elements have different atomic mass
atom mass have nothing to do with elemental identity
what is mean by vector
Answer:
A quantity having direction as well as magnitude is called vector.
It id desired to increase thr volume of gas by 20% without changing the pressure .To what temperature the gas must be heated if the initial temperature of the gas is 27degree celcius?
Answer:
32.4°C
Explanation:
Consider the following expression:
P•V/T =P'•V'/T'
Where P and P' are respectively the initial and the final pressure, V and V's are respectively initial and final volume, and T and T' are respectively initial and final temperature.
We know that the pressure cannot change, so it means that P = P'
We also know that the volume must be increased in 20%, and if we multiply the volume by 1.2 is like increase it in 20%, so we can write that V' = 1.2•V, and changing a little more we can write that V'/V = 1.2
So let's do some maths:
P•V/T = P'•V'/T'
T'•P•V/T = P'•V'
T'•P•V = P'•V'•T
T'=P'•V'•T/P•V
We know that P'=P so the division is equal to 1:
T'= 1•V'•T/V
We also know that V'/V = 1.2, so:
T' = 1.2•T
And we know the value of T, it's 27, so now we just have to solve it:
T' = 1.2•27
T' = 32.4°C