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.
20. Which of the following elements would you expect to lose one electron? Select all that apply.
.
Fluorine
Potassium
Chlorine
Sodium
Answer:
Sodium and Potassium only
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
Which electromagnetic wave type has frequencies higher than the violet of visible light?
Answer:
Ultraviolet means “above violet.” The electromagnetic frequencies of ultraviolet radiation (UV) extend upward from violet, the highest-frequency visible light.
hope this helps
What is Most likely true about forensic scientist
Answer:
They collect all of the evidence for cases
Explanation:
A car starts from rest and accelerates at 2.5m/s^2 for 2s. What is the final velocity of the car
[tex]\begin{gathered}\boxed{\begin{array}{c}\\ {\pmb{\sf{Three \: equation \: of \: motion}}} \\ \\ \sf \star \: v \: = u \: + at \\ \\ \sf \star \: s \: = ut + \: \dfrac{1}{2} \: at^2 \\ \\ \sf \star \: v^2 - u^2 \: = 2as\end{array}}\end{gathered}[/tex]
Calculation :-[tex]\pink{\qquad \pmb{ \sf\longrightarrow v \: = u \: + at}}[/tex]
[tex] \qquad \pmb{\sf \longrightarrow v = 0 + 2.5 \times 2}[/tex]
[tex]\qquad \pmb{ \sf\longrightarrow v = 0 + 5}[/tex]
[tex] \qquad \pmb{\sf \longrightarrow v = 5 \: ms^{-1}}[/tex]
[tex]\qquad \longrightarrow {\pink{\underline{\underline{\pmb{\sf{ Final \: velocity= 5 \: ms^{-1} }}}}}}[/tex]
Henceforth –
The final velocity of the car is 5 m/s▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
For accurate answer i will mark you a brainlist:D
How will you convert 85 cm to 85 m, choose one of the following option:
( Remember there is a decimal in 85 after 5)
Question 12 options:
Move the decimal in 85 TWO places to the right to decrease the value.
Move the decimal in 85 THREE places to the right to increase the value.
Move the decimal in 85 TWO places to the Left to decrease the value.
Move the decimal in 85 THREE places to the Left to decrease the value.
Answer:
welp it would be this option : Move the decimal in 85 TWO places to the right to decrease the value.
Explanation:
Answer:
Option A
Explanation:
Moving the decimal point 2 places to the right will give you 8500 cm=85m
help asap for brainlist
The melting and boiling point tests will MOST help them to infer the strength of intermolecular forces between ionic and covalent compounds?
Question 12 options:
True
False
Answer:
True po
Explanation:
Sana nakatutulong
#Carry on learning
Ionic compounds have higher melting and boiling point than covalent compounds, since ionic bonds are stronger than covalent bonds. Hence, we can compare the intermolecular forces using melting or boiling points.
What is boiling point?Boiling point of a substance is the temperature at which the substance changes from liquid state to gaseous state. Melting point is the temperature at which the substance changes from solid state to liquid state.
Both melting point and boiling point depends on the bond type, molecular weight, temperature and pressure. Stronger the bond , higher energy needed to weaken the intermolecular force between molecules to convert them to liquid state or vapour state.
Hence, the temperature that have to be applied to loosen the bonds to boil them or melt them increases as bond strength increases. Therefore, these physical quantities definitely helps to infer the strength of bonds.
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how long does it take for chlorine to evaporate from water?
Answer:
1 to 5 days
Explanation:
Which of the following states of matter is made of free electrons and ions of the elements? A. liquid B. gas C. solid D. plasma
Answer:
D. Plasma
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 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.
A gas occupies a volume of 120 mL at 700 mm Hg. What will happen to the volume of the gas if the pressure is changed to 1500 mm Hg at constant temperature
Answer:
56 mLExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
From the question we have
[tex]V_2 = \frac{700 \times 120}{1500} = \frac{84000}{1500} = \frac{840}{15} \\ = 56[/tex]
We have the final answer as
56 mLHope this helps you
What are the diffrent types of chemical reactions?
A chemical reaction is a process that can lead to a change of state, the outcome of a chemical reaction can ultimately lead to the formation of a new substance.
Types of Chemical ReactionsSynthesis reactionsDecomposition reactionsSingle-replacement reactionsDouble-replacement reactionsCombustion reactions.Learn more about chemical reaction here:
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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
0.0200 moles of a compound is found to have a mass of 1.64 g. Find the formula mass of the compound
Give your answers to 3 significant figures
Answer: 82.0 g/mole
Explanation:
Use the units to see that if we divide 1.64 grams by 0.0200 moles, we'll get a number that is grams/mole, the definition of formula mass.
1.64/0.0200 = 82.0 g/mole (3 sig figs)
We can't tell from this alone what the molecular formula might be, but C6H10 (cyclohexene) comes close (82.1 grams/mole).
The formula mass of the compound will be approximately 82.0 g/mol
The formula mass of the compound is the sum of atomic masses of all the atoms in its chemical formula. It is calculated by adding up the atomic masses of the individual elements in the compound, each multiplied by the subscript indicating the number of atoms of that element in the formula.
To find the formula mass of the compound, we'll use the relationship between moles, mass, and molar mass.
Molar mass (in g/mol) = Mass (in g)/Moles
Given:
Mass = 1.64 g
Moles = 0.0200 moles
Let's plug the values and calculate molar mass:
Molar mass = 1.64 g / 0.0200 moles
Molar mass ≈ 82.0 g/mol
The formula mass of the compound is approximately 82.0 g/mol, rounded to three significant figures.
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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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Please help me, I'm stuck and I don't know how to do it.
How many atoms are there in 7.02 g Si ?
Answer:
1.51e23 atoms
Explanation:
First, using the molar mass of Si (28.1 g/mol), determine the # of moles of Si we have. Then use Avogadro's number (6.022e23 atoms = 1 mol) to convert the # of moles to the # of Si atoms.
(7.02 g Si)([tex]\frac{1 mol}{28.1 g}[/tex]) = 0.250 mol Si
(0.250 mol Si)([tex]\frac{6.022*10^{23} atoms }{1 mol}[/tex]) = 1.51e23 atoms
The atomic mass of Silicon (Si) is 28.09 g/mol. The no. of atoms present in 7.02 g of Si is 1.46 × 10²³.
What is a mole?Any substance containing 6.022 × 10²³ atoms is called one mole of that substance. The no.of moles can be calculated by dividing the given weight by the atomic mass of the substance.
Atomic mass of Si = 28.09 g/mol
Given mass = 7.02 g.
No.of moles = 7.02 g/ 28.09 g/mol
= 0.24 moles
One mole contains 6.02 × 10²³ atoms. Thus 0.24 mole of Si contains 6.02 × 10²³ × 0.24 = 1.46 × 10²³ atoms.
Hence, no.of atoms present in 7.02 g of Si is 1.46 × 10²³ .
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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
2. How many of valence electrons do the elements in column 4 have? Are these elements very reactive?
Explain your answer.
Answer:
4
Explanation:
Elements in group 14 have 4 valence electrons. Meaning that to achieve a stable octet they need to either gain or lose 4 electrons in total.
Define valence electrons.
Answer:
Electrons on the outermost shell of an atom. They are responsible for the chemical properties of an atom.
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
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?
Answer:
Our body loses heat by the evaporation of sweat, which is like a tea kettle boiling on a stove top. Both are being heated through conduction, the tea kettle from the stove top and the sweat from our body.
Explanation:
Hope this helps!
Which two factors will improve the efficiency of an inclined plane?
the answer is using rollers in conjunction with inclined plane.
Why are reforestation and reclamation important to environmental health?
Answer:
Reforestation can be used to undo and rectify the effects of deforestation and improve the quality of human life by absorbing pollution and dust from the air, rebuilding natural habitats and ecosystems,reducing global warming via biosequestration of atmospheric carbon dioxide, and harvesting for resources, particularly.
Explanation:
I need the answer of these questions
Answer:
36. B, LATTICE
35. A, COVALENT
38. B, TRIPLE COVALENT
Explanation:
36: Lattice- Sodium chloride is taken as a typical ionic compound.
35. covalent - the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons.
38. TRIPLE COVALENT- because each nitrogen atom needs three electrons to fill its outermost shell.
-----
I hope it help
What is the chemical name of NaCl₂
Answer:
It’s sodium chloride
Explanation:
Hope that helps
Which option is a key point of cell theory? Cells can repair neighboring cells, but not themselves.Cells can repair neighboring cells, but not themselves. , , Cells are the basic structural unit of all living organisms.Cells are the basic structural unit of all living organisms. , , All cells that make up an organism are similar to each other.All cells that make up an organism are similar to each other. , , Some cells can burn food molecules to release energy, but some cannot.
Answer:
Cells are the basic structural unit of all living organisms.
Explanation:
Hope this helps, but i'm unsure if it would be multiple choice or not.
Describe the physical properties of Copper (Cu) based on what you know about metals, nonmetals, and metalloids
Answer:
Copper is reddish brown color
Its density is 8.93 g cm-3
highly malleable at ordinary temp, but is brittle near its melting point
god conductor of heat and electricity
Explanation:
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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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: