Moles of Aluminum needed : 0.8
Further explanationGiven
1.2 moles H₂
Required
moles of aluminum
Solution
The reaction coefficient in a chemical equation shows the mole ratio of the components of the compounds involved in the reaction (reactants and products)
Reaction(balanced equation)
2Al + 6 HCl = 2AlCl₃ + 3H₂
From the equation, mol ratio of Al : H₂ = 2 : 3, so mol Al :
= 2/3 x mol H₂
= 2/3 x 1.2
= 0.8 moles
If there are 50 grams of a radioactive element how much will be present after 1,2, and 3 half lifes
Answer:
6.25
Explanation:
PLeaseeeeeee ANSWERRR
Answer: looks like A
Explanation:
Helga has a box. She wants to determine how much the box can hold. Which measurement should she calculate?
A) Length
B) Area
C) Volume
D) Perimeter
C) volume
Explanation:
hope it helps !
Answer:
Volume. "How much the box can hold" means how much matter can fit into the box
need help with physical changes
Answer:
I give u three in explanation
Explanation:
Crushing the can, stomping on the can, and squishing the can
Which is an example of chemical change?
Answer:
Burning, cooking, rusting and rotting are examples of chemical changes. i) How does the atomic radius change as you go
a) From left to right in a period?
b) Down a group in the periodic table?
Answer:
In general, the atomic radius decreases as we move from left to right in a period and it increases when we go down a group. This is because in periods the valence electrons are in the same outermost shell. The atomic number increases within the same period while moving from left to right which in turn increases the effective nuclear charge.
Explanation:
Jacqueline is interested in helping her overweight cat lose weight so that he will be healthier and more active. She selects a new cat food based on the label’s claim that it can help with weight loss. Jacqueline measures out the food carefully each day, has been weighing the cat every 48 hours, and records the measurement. What keeps this practice from being a scientific experiment? A. There is only one cat and one type of food being used. B. The cat should be weighed every day to collect more data. C. She has not considered whether the cat will like the new food. D. The food is not the brand that Jacqueline’s friend used for his overweight
Answer:
sorry bro / sis this is too long question soo try by yourself
Define terms element compound
Answer:
Elements are the simplest complete chemical substances.
Each element corresponds to a single entry on the periodic table.
An element is a material that consists of a single type of atom.
A compound consists of two or more types of elements held together by covalent or ionic bonds
Chemists once believed that an atom was made of negative electrons dispersed inside a positive mass like raisins in pudding. An experiment with radiation and gold foil demonstrated that most of an atom was
made of empty space. After this experiment, they adopted a new model of the atom that showed the electrons orbiting the nucleus of the atom from a distance. Which of the following statements about the new
model is true?
The new model is perfect and will not change.
The new model is a wrong model and will not last.
The new model fits the data worse than the old model.
The new model fits the data better than the old model.
the new model fits the data better than the old model
The true statement about the new model is the new model fits the data better than the old model. The correct option is b.
What is Rutherford’s gold foil experiment?In Rutherford's gold foil experiment, he discovered that most particles passed through the gold foil, some were distributed in other directions, and very few were redirected back toward the source.
Because all the particles would pass through without being deflected if there was a symmetrical distribution of charges, this experiment proves that the plum pudding model was erroneous.
Rutherford’s gold foil experiment demonstrated how tightly packed the positive charge is within the atom. This was a better experiment.
Thus, the correct option is b. The new model fits the data better than the old model.
To learn more about Rutherford’s gold foil experiment, refer to the below link:
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please help! you are amazing! also brainliest :)
Which list is in order from biggest to smallest?
A. Universe - Galaxy - Solar system - Earth
B. Earth - Solar system - Nebula - Galaxy
C. Solar system - Galaxy - Nebula - Earth
D. Universe - Earth - Solar system - Nebula
im pretty sure its A if i did all my reasearch right.
hope this helps luv. <3
Answer:
is A
Explanation:
Universe - Galaxy - Solar system - Earth
Brainliest plz
Hope it work
__ is a spark caused when electricity that has built up in a thunderhead discharges
Answer:
Lightning
Explanation:
Lightning is a spark caused when electricity that has built up in a thunderhead discharges.
During ionic bonding, there must be a chemical interaction between...
O metallic elements, only
O nonmetallic elements, only
O one metallic and one nonmetallic element, only
O metalloids ,only
please help, its science ->-
Answer:
quantitative
Explanation:
yrup, USP, is prepared by dissolving 850 g of sucrose in sufficient purified water to make 1000 mL of syrup. Syrup has a specific gravity of 1.31. How many milliliters of water are used to prepare two liters of syrup?
Answer:
920mL of water
Explanation:
To solve this question we need to find as first the mass that must be added of water to make 1000mL of syrup using specific gravity. Thus, we can know the volume of water that mus be added:
1.31 is 1.31g/mL. In 1000mL = 1310g/1000mL. As the mass added of sucrose is 850g, the mass of water = Volume of water is:
1310g - 850g = 460g of water = 460mL to make 1L, To make 2L the amount of water that must be added is:
460mL * 2 =
920mL of waterThe number of milliliters of water are used to prepare two liters of syrup is 920 mL of water.
Given that,
USP, is prepared by dissolving 850 g of sucrose in sufficient purified water to make 1000 mL of syrup. The Syrup has a specific gravity of 1.31.Based on the above information, the calculation is as follows:
1.31 is = 1.31g/mL.
Now
In 1000mL = [tex]1310g \div 1000mL[/tex].
Now if the mass is added so the mass of water should be equivalent to the volume of the water.
= 1310g - 850g
= 460g of water
Now
= 460mL for 1L,
To make 2L the water should be
= 460mL (2)
= 920mL of water
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How many atoms are in 3.8 mol of calcium? Round your answer to 2 decimal places.
Answer:
[tex]\boxed {\boxed {\sf 2.29 *10^{24} \ atoms \ Ca}}[/tex]
Explanation:
To convert from moles to atoms, we must use Avogadro's Number.
[tex]6.022*10^{23}[/tex]
This number tells us the number of particles (atoms, molecules, ions, etc.) in 1 mole. In this case, the particles are atoms of calcium (Ca).
[tex]6.022*10^{23} \ atoms \ Ca / 1 \ mol \ Ca[/tex]
1. Convert from moles to atoms.
Write Avogadro's number as a fraction.
[tex]\frac {6.022 *10^{23} \ atoms \ Ca} {1 \ mol \ Ca}[/tex]
Multiply the given number of moles of calcium (3.8) by the fraction created.
[tex]3.8 \ mol \ Ca *\frac {6.022 *10^{23} \ atoms \ Ca} {1 \ mol \ Ca}[/tex]
The moles of calcium will cancel.
[tex]3.8 *\frac {6.022 *10^{23} \ atoms \ Ca} {1 }[/tex]
The denominator of 1 is insignifcant and we can turn this into a simple multiplication problem.
[tex]3.8 * {6.022 *10^{23} \ atoms \ Ca}[/tex]
[tex]2.28836*10^{24} \ atoms \ Ca[/tex]
2. Round
The problem tells us to round to 2 decimal places or the hundredth place.
[tex]2.28836*10^{24} \ atoms \ Ca[/tex]
The 8 in the thousandth place tells us to round the 8 to a 9.
[tex]2.29 *10^{24} \ atoms \ Ca[/tex]
There are about 2.29*10²⁴ atoms of calcium in 3.8 moles.
Gases generally have Group of answer choices low density closely packed particles no decrease in volume when pressure is increased no increase in volume when temperature is increased high density
Answer:
Low density
Explanation:
The answer to this question is low density as Gases in general have low densities as their particles are very far apart. Their inter-molecular spaces are actually large. And The number of molecules per unit volume in a gas are small when we put them in comparisons with solids and liquids. That is why they have low densities.
I hope this answers your question.
In a piece of copper, where would you find the valence electrons?
moving freely between the cations
shared between a cation and anion
attached to a cation
attached to an anion
PLEASE HELP ASAP!!
Answer:
answer is A
Explanation:
just took test
have a good day :)
In a piece of copper, the valence electrons move freely between the cations. Therefore, option (A) is correct.
What are valence electrons?Valence electrons can be defined as the electrons present in the outermost shell of an atom whereas the electrons occupying the inner shell are known as core electrons. Lewis structures can be helpful to evaluate the number of valence electrons and know the types of chemical bonds.
Valence electrons are occupied in different electron shells. These electrons participate in the interaction between atoms and cause the formation of chemical bonds.
Only electrons filled in the valence shell can contribute to the formation of a chemical bond between atoms and decide the reactivity of the element.
The electrons in the piece of copper move freely because the electrons are loosely bound electrons are responsible for the conductivity of the metal. The free movement of electrons in the electron sea is stabilized by the positively charged kernels.
Learn more about valence electrons, here:
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The p_______ scale is a color coded scale that identifies acids and bases and neutral substances. Acids are 1-_____ and bases are 8-_____. Neutral substance are ____ like water.
Answer: The pH scale is a color coded scale that identifies acids and bases and neutral substances. Acids are 1-7 and bases are 8-14. Neutral substance are neutral like water.
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
The pH scale is a color coded scale that identifies acids and bases and neutral substances. The colours from yellow to red indicate an acidic solution, colours blue to violet indicate base and green colour indicates that a solution is neutral.
Acids have pH ranging from 1 to 6.9, bases have pH ranging from 7.1 to 14 and neutral solutions have pH equal to 7. Thus pH scale range from 1 to 14.
Water is neutral with a pH of 7.
Plzzzzz helppppp it’s due already I’ll mark Brainly
Question 1/5
Which of the following is not required to define a material as a mineral?
A. useful
B. naturally occurring
C. solid
D. has a crystal structure
One glass of water is 85 degrees F and another is 40 degrees F. When an Alka Seltzer tablet is dropped into each glass, at the same time, which of the following describes the expected results? The 85 degree F glass will have an accelerated chemical reaction, because the water was warmer.
The 85 degree F glass will have an accelerated chemical reaction, because the water is cooler.
The 40 degree F glass will have an accelerated chemical reaction, because the water is cooler.
The 40 degree F glass will have an accelerated chemical reaction, because the water was warmer.
Answer:
The 85 degree F glass will have an accelerated chemical reaction, because the water was warmer.
Explanation:
The glass of water with the higher temperature will have an accelerated chemical reaction because the water is warmer.
The rate of chemical reaction is directly proportional to the temperature changes.
As temperature increases so is the reaction rate.
Temperature is directly proportional to the average kinetic energy of reacting particles. So, the glass water at a higher temperature will have a faster reaction. The elevated temperature ensures increase in frequency of colliding particles in the reaction.PLSS HELP! The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (4 points)
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
The answer is option A..
The relative number of atoms of a compound can be calculated
by dividing the percentage of an element by the:
Answer:
Obtain the relative numbers of atoms of each element in the compound by dividing the number of moles of each element in the 100 g sample by the number of moles of the element present in the smallest amount.
Answer:
Obtain the relative numbers of atoms of each element in the compound by dividing the number of moles of each element in the 100 g sample by the number of moles of the element present in the smallest amount.
What type of energy is caused by positive and negative charges in matter
Answer:
Static electricity is the result of an imbalance between negative and positive charges in an object. These charges can build up on the surface of an object until they find a way to be released or discharged.
Explanation:
What temperature is absolute zero in Fahrenheit?
Answer:
-460 Im pretty sure
Explanation:
What type of fish is this?
Answer:
Angel Fish!
Explanation:
Answer:
Angel fish, the other person answered first tho.
Explanation:
If a concentrated solution of acetic acid is 99.5 % HC 2 H 3 O 2 and has a density of 1.05 g/mL, what is the concentration of this acid in moles per litre?
The concentration of this acid in moles per litre : 17.41
Further explanationGiven
99.5% acetic acid
density=ρ=1.05 g/ml
Required
the concentration (mol/L)
Solution
99.5% dan density 1.05 g/ml (MW acetic acid = 60 g/mol)
[tex]\tt 99.5\%\times 1.05\dfrac{g}{ml}\times \dfrac{1000~ml}{L}=1044.75~g/L\\\\\dfrac{1044.75~g/L}{60~g/mol}=17.41~mol/L[/tex]
the melting point of gallium metal is 29.76°C If a piece of gallium is sliced into three parts, the melting point will be:
A. higher than 29.76°C
B. 29.76°C
C. lower than 29.76°C
Answer: B. 29.76°C
Explanation:
The melting point is known as an intensive property of matter. This means the melting point is not affected by the amount of mass. Whether the metal is really large or small, the melting point of gallium (Ga) is roughly 29.76 degrees Celsius.
A 0.200 M NaOH solution was used to titrate a 18.25 mL HE
solution. The endpoint was reached after 31.20 mL of titrant
were added. Find the molar concentration of the original HF
solution.
Answer:
M₂ = 0.34 M
Explanation:
Given data:
Molarity of NaOH =M₁ = 0.200 M
Volume of HF =V₂= 18.25 mL
Volume of NaOH added = V₁ = 31.20 mL
Molarity of HF solution = M₂ = ?
Solution:
M₁V₁ = M₂V₂
by putting values,
0.200 M × 31.20 mL = M₂ × 18.25 mL
M₂ = 0.200 M × 31.20 mL / 18.25 mL
M₂ = 6.24 M.mL / 18.25 mL
M₂ = 0.34 M
The total number of the elements above with 2 valence electron is ____.
Answer:
four elements
Explanation:
He = 1s²
Be = 1s² 2s²
C = 1s² 2s² 2p²
Mg = 1s² 2s² 2p⁶ 3s²
Si = 1s² 2s² 2p⁶ 3s² 3p²
Ca = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Valence electrons are those electrons which are present in outer most electronic shell.
He, Be, Mg, Ca these four elements have 2 valence electrons.
While Si and C have four valance electrons.
The total number of the elements above with 2 valence electron is four.
The electronic configurations of the elements are given:
He = 1s²
Be = 1s² 2s²
C = 1s² 2s² 2p²
Mg = 1s² 2s² 2p⁶ 3s²
Si = 1s² 2s² 2p⁶ 3s² 3p²
Ca = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Valence electrons are those electrons which are present in outer most electronic shell.
He, Be, Mg, Ca these four elements have 2 valence electrons.Learn more:
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