Answer:
1 cg = 10 mg
Explanation:
So, 89cg = 89 * 10 = 890mg!
Pls thank, 5star, and brainliest!
nuclear energy is created through the process of splitting apart atoms and releasing large amounts of heat energy that can be converted to electrical energy.this process is known as?
how many moles are in 1.2 x 10^26 molecules of calcium hydroxide
Answer:
199.26 or with sig figs 2.0 x 10^2
Explanation: you take the # of molecules and divide it by avagadros number which is 6.022141 x 10^23
List four rules for rounding numbers.
Answer:
the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up. Example: 38 rounded to the nearest ten is 40
If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down. Example: 33 rounded to the nearest ten is 30
Rounding fractions works exactly the same way as rounding whole numbers. The only difference is that instead of rounding to tens, hundreds, thousands, and so on, you round to tenths, hundredths, thousandths, and so on.
By rounding off, you could easily figure out that you would need about $6.00 to pay for your groceries.
1. How many moles of Boron is 1.25 x 1023 atoms of Boron? *
O 0.208 mol B
0 7.53 x 1046 mol B
O 1.35 x 1025 mol B
0 4.82 mol B
Answer:
0.208 mol B
Explanation:
There are 6.02 × 10^23 atoms in one mole of a substance, according to Avagadro's law.
According to this question, there are 1.25 x 10^23 atoms of Boron. This means that the number of moles in the Boron atom can be calculated thus:
number of moles (n) = number of boron atoms (nA) ÷ Avagadro's number
n = 1.25 x 10^23 ÷ 6.02 × 10^23
n = 0.2076 × 10^(23-23)
n = 0.208 × 10^0
n = 0.208 × 1
n = 0.208 moles of Boron
HURRY!!!! TIMED!!! WILL GIVE BRAINLIST!!!
A 10.0 g sample containing calcium carbonate (CaCO3) and an unreactive material was placed in excess hydrochloric acid, HCl. A reaction occurred, producing calcium chloride (CaCl2), water, and carbon dioxide. (a) write a balanced equation for the reaction (b) when the reaction was complete, 800 mL of carbon dioxide gas was collected. How many moles of calcium carbonate were used in the creation? (c) How many grams of CaCO3 were used? (d) If there was another contaminant in the sample that was not unreactive, would this have caused the percent yield of carbon dioxide to be higher, lower, or the same, explain your answer.
Explanation:
(a) write a balanced equation for the reaction
CaCO3 + HCl --> CaCl2 + H2O + CO2
The balanced equation is given as;
CaCO3 + 2HCl → CaCl2 + H2O + CO2
(b) when the reaction was complete, 800 mL of carbon dioxide gas was collected. How many moles of calcium carbonate were used in the creation?
From the balanced reaction;
1 mol of CaCO3 reacts to produce 1 mol of CO2
1 mol of CO2 = 22.4 L of CO2
This means;
1 mol of CaCO3 reacts to produce 22.4L of CO2
x mol would produce 800ml (0.8 L) of CO2
1 = 22.4
x = 0.8
x = 0.8 * 1 / 22.4 = 0.0357 mol
(c) How many grams of CaCO3 were used?
Mass = Number of moles * Molar mass
Molar mass of CaCO3 = 100.0869 g/mol
Mass = 0.0357 mol * 100.0869 g/mol = 3.57 g
(d) If there was another contaminant in the sample that was not un reactive, would this have caused the percent yield of carbon dioxide to be higher, lower, or the same, explain your answer.
The same
An un reactive contaminant in the sample is most likely a catalyst. Catalysts only affect the rate of reaction. They do not affect yields of products.
1) How many atoms are in Molecules? O One O Exactly two O Two or more O Compounds don't have atoms
Answer:
Two or more!
Explanation:
How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions?
1. They used X-ray analysis.
2. They used litmus testing.
3. They burned the paint to examine what elements were left after the chromium was burned off.
4. They studied the density of modern yellow paint to that of 100-year-old paint.
Answer:
I think the answer is A - they used X-ray analysis.
Explanation:
Answer:They used X-ray analysis
Explanation:
It’s in the text
David walks 10 Km North. He turns East and walks 10 more Km. What is his distance
Answer:
20 km
Explanation:
he walks 10 km + another 10 km so 20 :)
The nucleus of an atom contains ________________________________________.
Answer:
protons(positively charged) and the neutrons (no charge)
Explanation:
Answer:
The nucleus of an atom contains protons and neutrons.
What would be the mass of 3 moles of water molecules?
a
54 grams
b 40 grams
C
30 grams
d 20 grams
Answer:
[tex]\boxed {\boxed {\sf A. \ 54 \ grams }}[/tex]
Explanation:
To convert from moles to grams, we must use the molar mass.
Recall that water's molecular formula is H₂O. It contains hydrogen and oxygen. Look up the two elements masses on the Periodic Table.
Hydrogen (H): 1.008 g/mol Oxygen (O): 15.999 g/molNow, use these masses to find water's mass. The subscript of 2 tells us there are 2 atoms of hydrogen, so we multiply hydrogen's mass by 2 and add oxygen's.
H₂O= 2(1.008 g/mol) + 15.999 g/mol = 18.015 g/molUse the molar mass as a ratio.
[tex]\frac{18.015 \ g \ H_2 O}{ 1 \ mol \ H_2 O}[/tex]
Multiply by the given number of moles.
[tex]3 \ mol \ H_2O*\frac{18.015 \ g \ H_2 O}{ 1 \ mol \ H_2 O}[/tex]
The moles of water will cancel.
[tex]3 *\frac{18.015 \ g \ H_2 O}{ 1 }[/tex]
[tex]3 *{18.015 \ g \ H_2 O}[/tex]
[tex]54.045 \ g \ H_2O[/tex]
Round to the nearest whole number. The 0 in the tenth place tells us to leave the number as is.
[tex]54 \ g \ H_2O[/tex]
There are about 54 grams of water in 3 moles.
Answer:
54 grams
Explanation:
First step is to find what one mole of water is in grams.
Water is H2O so that means we have two moles of Hydrogen.
H - 2 grams (on periodic table)
We have one mole of Oxygen.
O - 16 grams (on periodic table)
Add 2 and 16 to get 18 total grams in one molecule of H2O
Now multiply 3 times 18 to know how many grams in 3 moles of H2O
You end with
3x18=54 grams
How many molecules of nitrogen dioxide (NO2) can be produced from 4 moles
of oxygen (O2)? *
The number of molecules of Nitrogen dioxide : = 4.816 x 10²⁴
Further explanationGiven
4 moles of Oxygen(O2)
Required
The number of molecules
Solution
Reaction
2NO + O2 ⇒ 2NO2
From the equation, mol NO2 :
= 2/1 x mol O2
= 2/1 x 4 moles
= 8 moles
The number of molecules :
= 8 x 6.02 x 10²³
= 4.816 x 10²⁴
what type of bond is Cl and Br?
Answer: Polar bond
Explanation:
How many atoms of silver are in a bracelet that has a mass of 13.94 grams?
Number of Silver atoms : N = 7.8 x 10²² atoms
Further explanationGiven
mass of bracelet : 13.94 g
Required
Number of atoms
Solution
Assuming the bracelet consists entirely of silver
mol of silver :
= mass : molar mass
= 13.94 g : 107,8682 g/mol
= 0.129
Number of atoms :
N = n x No(No = Avogadro's number)
N = 0.129 x 6.02 x 10²³
N = 7.8 x 10²² atoms
Dana is playing with her friends. They ride their scooters 20 meters down the road North. They stop to grab a drink of water. Feeling tired, they turn around and ride their scooters 20 meters south
What is Dana and her friend’s displacement
Answer:
what is the displacement
Explanation:
True/False: All of the elements combine in a variety of ways to make up all living and all nonliving things
Answer:
true
Explanation:
At certain times of year , the oceans get warmer. Which part of the water cycle is directly affected by the warming of the ocean water?
How many moles of S2 are needed to produce 1.50 moles of SO2 gas
Answer:
1.5moles of S;
Explanation:
The reaction expression is given as:
S + O₂ → SO₂
Number of moles of SO₂ = 1.5moles
From the balanced reaction expression:
1 mole of SO₂ will be produced from 1 mole of S;
So; 1.5moles of SO₂ will produce 1.5moles of S;
The moles of S₂ needed to produce 1.50 moles of SO₂ gas is 1.5 mol.
What are moles?The mole is a SI unit of measurement that is used to calculate the quantity of any substance.
The reaction is
S + O₂ → SO₂
The number of moles of SO₂ is 1.50 mol
1 mole of S produce 1 mole of SO₂
Then, 1.5 mole of S will produce 1.5 SO₂
Thus, the moles are 1.5.
Learn more about moles
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Wastewater filtration
Pros and cons of secondary water filtration?
which element group makes computers and calculators
How many moles of Na2SO4 are present in 426.12 grams of Na2SO4? (5 points)
Group of answer choices
2
3
5
6
Answer: It’s 2.9 moles
Explanation:
Answer:
b) 3
Explanation:
i got it right
What is the oxidation number for Cl?
2
+1
-1
+2.
Answer:
-1
Explanation:
Why can single bonds rotate freely?
Scientists often need a catalyst to start a chemical reaction. They need to apply heat, acids, or other materials to jump-start the experiment.
Which phrase is the best definition of catalyst?
A. something hot
b. something acidic
c. something that triggers
d.something that is scientific
Answer:
something that triggers
Explanation:
a catalyst helps move a reaction along
A catalyst shows some specificity in its action. It speeds up only a spontaneous reaction. The best definition of catalyst is something that triggers. The correct option is C.
What is a catalyst?A substance which increases the rate of a chemical reaction without itself undergoing any permanent change chemically or quantitatively is defined as the catalyst and the phenomenon is called catalysis.
It is believed that a catalyst actually participates in the chemical reaction that is speeds up. It forms temporary bonds with the reactants yielding an intermediate activated complex.
A typical example of catalyst is iron (Fe) which is used in the Haber process for the manufacture of ammonia. The catalyst is recovered unchanged in amount and chemical composition at the end of the reaction.
In most cases, a small amount of a catalyst can speed up reaction between large amounts of reactants. A catalyst shows maximum efficiency at optimum temperature.
Thus the correct option is C.
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How is heat transferred through space
Heat is transferred by energy waves moving through space. Explanation: According to research: Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is invisible
Please give brainiest if possible, I kinda need it. Thnx!
Answer:
the transfer of energy through space is called radiation. through radiation there is no direct contact between heat source and object. sunlight radiation warms the earth's surface; radiation can also come from fires.
The stability of atomic nuclei is most affected by the
a)number of N
b) number of e
c) number of P
d) ratio of N to P
ASAP PLZZ
Why are we able to see planets at night?
Answer: Because planets do not have nuclear fusion, they do not produce their own light. Instead, they shine with light reflected from a star. When we see planets in the night sky, such as Venus, the so-called "Evening Star," we're seeing reflected sunlight.
Explanation:
V7
Which of the following is a MIXTURE. Select ALL that apply.
(0/1 Point) a:brass
b:calcium
c:sodium chloride
d:apple juice
Answer:
sodium chloride
Explanation:
According to the Heisenberg uncertainty principle, it is impossible to know both the __ and __ of an electron simultaneously.
a. mass and charge
b. position and velocity
c. mass and position
d. velocity and charge
Answer:
C
Explanation:
It's simple because there were so many quantitative analysis of error and they didn't had the kind of observations as we have now
A2B8 + C2 - B2C + AC2
Answer:
You need to put more info! If you are trying to find the GCF its 1
Someone help it’s due today
Answer:
All elements are neutral
Explanation:
The plum pudding model of the atom indicated that all elements are neutral. The model was proposed by J.J Thomson after he conducted his experiment on the gas discharge tube.
From the experiment he discovered electrons which he called cathode rays.
Therefore, he suggested the plum pudding model of the atom.
The model describes negatively charge sphere surrounded by positive charges to balance them.