The half-life of Palladium-100 is 4 days. After 16 days a sample of Palladium-100 has been reduced to a mass of 6 mg. What was the initial mass (in mg) of the sample
Answer:
96mg
Explanation:
Since the half-life of Palladium-100 is 4 days and the sample has been reduced after 16 days, that means the sample has undergone four half-lives. To find the intial mass, just work backwards:
6 x 2= 1212 x 2= 2424 x 2= 48 48 x 2= 96As you see, I've worked backwards from the four half-lives. So the initial mass after 16 days is 96 mg.
What is an electrolysis
Answer:
Definition of Electrolysis :- Electrolysis, process by which electric current is passed through a substance to effect a chemical change. The process is carried out in an electrolytic cell, an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions.Explanation:
Hope this helps you dear ✌️Carry on learning !!Is pure air an element, compound, or solution?
Air is mixture.
But pure air compound .
Explanation:
So the answer is Compound.
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why are baseballs harder to pick up tennis balls?
Explanation:
Because baseballs are made out of things that make it heavier then tennis balls, easier to play the sport. that's why they use a bat in baseball.
which characteristic do valence electrons indicate about reactions between atoms?
Bond number
The characteristic of reactions that depends on valence electrons is the bond type.
In chemistry, a chemical bond could be;
Ionic
Covalent
The type of bond formed depends on the number of valence electrons present. When there are few valence electrons on an atom, it mostly forms ionic bonds.
When there are more electrons on an atoms, it mostly forms covalent bonds and the electrons between the atoms are shared.
Describe the 3 dimensional NaCl lattice.
NaCl has a cubic unit cell, best thought of as a face-central cubic array of anions with an interpenetrating FCC action lattice or (vice versa). The cell looks the same whether you start with anions or cations on the corners. Each ion is 6 co-ordinates and has a local octahedral geometry.
NaCl lattice exhibit cubic unit cell. The face-centered cubic array of anions with an interpenetrating fcc cation lattice are seen in 3D structure. Each ion is 6-coordinate and has a local octahedral geometry.
What is sodium chloride?Sodium chloride is an ionic compound, formed from the sodium metal and chlorine atom. The ionic bond is formed by loss of one electron from sodium metal to the chlorine atom.
The lattice structure of all metals contains a pool of cations in the sea of mobile electrons. The electrons can be delocalized into the interstices and thus metals conduct electrically and thermally.
In the fcc lattice of NaCl, sodium atoms are arranged at the corners and Cl atoms are at the center of each cube face of the cell. They are assumed to touch along face diagonals.
Atoms are arranged at the corners of the cube with another atom at the cube center also hence there will 4 atoms one unit cell.
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A 2.37 g sample of a substance suspected of being pure gold is warmed to 71.8 ∘C and submerged into 15.9 g of water initially at 24.3 ∘C. The final temperature of the mixture is 27.0 ∘C.
Answer:
specific heat capacity of the unknown is 629.66 J/kg C
Explanation:
As we know that gold is heated to 72.3 degree C and mixed with water at 24.8 degree C
Now the final temperature of the mixture is 26 degree C
here we can say that heat given by the gold = heat absorbed by the water
So we will have
Q_{in} = Q_{out}Q
in
=Q
out
2.62 s (72.3 - 24.8) = 15.6 (4186) (26 - 24.8)2.62s(72.3−24.8)=15.6(4186)(26−24.8)
so we will have
s = 629.66 J/kg Cs=629.66J/kgC
so specific heat capacity of the unknown is 629.66 J/kg C
what does a large positive standard cell potential imply about the spontenty of the redox reaction occuring in teh cell
Answer : E cell standard is the potential difference between the two electrodes under standard conditions. Overall tendency for the redox reaction to occur spontaneously. A large positive E cell means the reaction is more spontaneous, and a negative E cell indicates a non spontaneous reaction.
Explanation: hope this answers your question
If a 435.767 g sample of bottled water contains 2.797 x 10-3 g of lead, what is the concentration of lead in the bottled water, in units of parts per million (ppm)
Answer:6.42 ppm
Explanation:ppm = (g soluto/g soluzione) ×1000000
Answer please
........................................
Answer:
The answer would be:
C. Potassium and magnesium
Explanation:
because the only have valence electrons
What structural characteristic do all of the atoms within a group (vertical columns) have in common?
Answer:
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
hope this helps
Explanation:
Each column is called a group. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements.
What is the formula for this ionic crystal?
Answer:
Al₄O₅
Explanation:
The key at the bottom tells us the blue spheres are oxygen atoms and the red spheres are aluminum atoms. By counting, there are 4 aluminum atoms and 5 oxygen atoms. Therefore, the formula is Al₄O₅.
Which of the following best describes the cell below
plant cell
Protist cell
Eukaryotic cell
Prokaryotic cell
Answer:
Prokaryotic cell
Explanation:
If you search it up you will see that the prokaryotic cell looks exactly alike with the picture you have posted.
Help
What is the correct orientation of the bar magnet, based on the magnetic field
lines shown?
A. South pole on the top edge and north pole on the bottom edge.
B. North pole on the top edge and south pole on the bottom edge
C. South pole on the left end and north pole on the right end
D. North pole on the left end and south pole on the right end
Answer:
b
Explanation:
north is up south is bottom
Answer:
C. South pole on the left end and north pole on the right end
Explanation:
From the figure, we can conclude that the poles of the magnet are on either sides of the magnet
Therefore, options 1 and 2 are excluded
It is a convention that the magnetic field lines move out of the north pole of a magnet and into the south pole of the magnet
From the figure, we can see that the magnetic field lines are moving out from the right end and into the left end
This means that the north pole is at the right end and that the south pole is at the left one
When a penguin gives a pebble to a potential mate, what behavior are they displaying?
A. Dance
B. Nest Building
C. Gift Giving
D. Vocalization
Answer:
Explanation:
b
What do all atoms in a period (horizontal rows) have in common?
Answer:
the same number of atomic orbitals.
Explanation:
Answer:
All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.
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Someone help me with this pls
The unbalanced equation below shows the reaction between sodium and water. In the reaction,
hydrogen gas is given off and sodium hydroxide is formed. The gas is collected and there is found to be
1.8 grams of hydrogen. What mass of sodium would have been used in this reaction?
Na + H2O + NaOH + H2
Answer:
41.4 g
Explanation:
2Na(s) + 2H2O (l) ----> 2NaOH ( aq) + H2 (g)
According to the above balnced chemical equation the ratio between moles of H2 gas formed to moles of Na used up is 1:2
Molar mass ( Mass of 1 mol) Of H2 gas is 2 gmol-1
So in 1.8 g of H2 0.9 mol should be present
Therefore no. of moles of Na used should be 2× 0.9 = 1.8 moles
Molar mass of Na= 23 gmol-1
So mass of 1.8 mol of Na = 1.8× 23 g = 41.4g
MULTIPLE CHOICE QUESTION
Which of the above represents a cell in an
isotonic solution?
B
А
C
Answer:
B
Explanation:
If you have a 100g of Boron and you want to find out how
many molecules of Boron you have, you would need to...
Answer:
5.57 x 10^24 atoms
Explanation:
first, you are seeking the number of ATOMS of Boron.
Boron has an Atomic mass of 10.8 g/mol (see #5 on the periodic table)
100 gm of Boron would have 100 g /10.8 g/mol =9.26 moles
each mole has Avogadros number of atoms 6.02 x 10^23
9.26 moles has 9.26 x 6.02 x 10^23 atoms =5.57 x 10^24 atoms
Which two factors will improve the efficiency of an inclined plane?
the answer is using rollers in conjunction with inclined plane.
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What happens when two positively charged objects move closer to each other?
A.Both charges become negative.
B.One charge becomes negative.
C.They will attract each other.
D.They will repel each other.
Answer: If two positive charges interact, their forces are directed against each other. The two charges repel each other.
Explanation: The same occurs with two negative charges, because their respective forces also act in opposite directions.) The electric field and resulting forces produced by two electrical charges of the same polarity.
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DO the postulates of daltons atomic theory explain the law of consrevetion of mass and thelaw of constant composition
Answer:
see answer
Explanation:
DO the postulates of Daltons atomic theory explain the law of conservation of mass and the law of constant composition.
Dalton's Atomic Theory Postulates1. Everything is composed of atoms, which are the indivisible building blocks of matter and cannot be destroyed or divided any further.
2. All atoms of a single pure element are the same in size and mass
3. Atoms of different elements vary from each other in size and mass.
4. Compounds are produced through different simple whole-number combinations of atoms to produce molecules.
5. Anywhere a compound exists, it will have the same atoms in the same ratio.
6. A chemical reaction between compounds is a re-arrangement of atoms
The law of conservation of mass is shown in 2, 4. and 5.
The law of constant co,position is shown in 2, 4, 5, and 6
what aspects are not accounted for in the ideal gas law?
The aspects not accounted for in the ideal gas law are the force of attraction of the gas molecules on each other and the volume of the gas molecules.
In the ideal gas law, it it assumed that the molecules of the gas are so far away from each other and thus they do not exert a significant force of attraction on each other. Also, the volume of each molecule of gas is neglected and assumed negligible and thus does not account for the overall volume of the gas.
So, the aspects not accounted for in the ideal gas law are the force of attraction of the gas molecules on each other and the volume of the gas molecules.
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Answer:
interactions between molecules
size of molecule
write a molecular, ionic, and net ionic equation for the reaction between solid magnesium carbonate and sulfuric acid.
Answer:
How to Write the Net Ionic Equation for H2SO4 + MgCO3 = MgSO4 + H2O + CO2 -
A net ionic equation also contains the spectator ions, whereas a net ionic equation just displays the chemical species that are involved in a process.
what is Net ionic equation?The net-ionic equation is a chemical equation that is used to express the condensed chemical reaction for a reaction that takes place in an aqueous solution. The ions involved in the production of a precipitate, water, or molecule are illustrated by the net-ionic equation. For precipitation, oxidation-reduction, and neutralization processes, net-ionic equations are frequently written.H₂SO₄ (aq) + MgCO₃ (s) →H₂O (l) + CO₂(g) + MgSO₄(aq)
An ionic equation is a chemical equation in which the electrolytes in aqueous solution are stated as dissociated ions. It is similar to a molecular equation in which substances are described as molecules.Learn more about the Net ionic equation with the help of the given link:
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When a bat hits a ball, what is the impulse?
a. the change in velocity multiplied by the force
b. the force multiplied by the time objects are in contact
c. the mass multiplied acceleration
d. the mass multiplied by the force
Answer:
The answer is B.
Explanation:
the force multiplied by the time objects are in contact
what is the mass of the product of 111.6g and 48g
Answer:
159.6
Explanation:
Due to the law of conservation of mass, mass is neither created nor destroyed in a chemical reaction. Hence, the mass of the product is the equivalent of the mass of the sum of the reactants.
The body also loses heat by the evaporation of sweat. How is a tea kettle boiling similar to the evaporation of sweat from the body?
Well they both leat sweat out, so they steam.
What is an element? Arrow
Answer:
One arrow is positioned in each box according to Hund's Rule which tells us to maximise the number of unpaired electrons in orbitals of the same subshell, and, to give those electrons the same "spin" (parallel spin).
Explanation:
What is the molar concentration of a solution prepared by dissolving 3.05 grams of sodium acetate in enough water to prepare 3.43 x 102 mL of the solution
Answer:
0.296 M
Explanation:
What is the molar concentration of a solution prepared by dissolving 3.05 grams of sodium acetate in enough water to prepare 3.43 x 102 mL of the solution
sodium acetate NaCH3COO has molar mas of
23 + 12 +24 + 1 +32 = 92 g/mol
3.05 g is 3.05 g/ 92 g/mol = 0.0328 moles
it is distributed over 102 mL = 0.102 L
its concentration is 0.0328/ 0.102 =0.296 M Mhttps://brainly.com/question/25586315?answering=true&answeringSource=feedPublic%2FhomePage%2F3#