5. Selenium-83 has a half-life of 25.0 minutes. How many minutes would it take for a 10.0
mg sample to decay and have only 1.25 mg of it remain?
Explanation:
10.0mg / 1.25mg = 8
1/8 of the original mass => 3 half-life phases
Hence it will take 25.0 min * 3 = 75.0min.
How did modern scientists experiment with Van Goghs paints to determine their chemical reactions?
Answer:
the would test random expirements
Can someone help me out?
Answer:
A
Explanation:
100 A can i get brainily
Suppose a lab procedure calls for 0.75 L of a 0.25 M CaCl2 solution. How much of a 10.0 M stock solution do we dilute?
Where the diluted solution is #2 (the numerator)
Answer:
V₁ = 0.019 L
Explanation:
Given data:
Molarity of stock solution = 10.0 M
Volume of stock solution = ?
Molarity of CaCl₂ = 0.25 M
Volume of CaCl₂ = 0.75 L
Solution:
Formula:
V₁ = M₂V₂ / M₁
V₁ = 0.25 M × 0.75 L / 10.0 M
V₁ = 0.1875 M.L / 10.0 M
V₁ = 0.019 L
Potassium nitrate has been used with charcoal and sulfur for centuries to make gunpowder. Using the Periodic Table provided in Canvas, Modules, General Information, determine the molar mass for potassium nitrate (KNO3).
Answer:
101.10200
Explanation:
Identify the molar mass of K, N, and O on the periodic table
K = 39.0983
N = 14.0067
O3 = 15.999×3 = 47.99700
Add them all together
39.0983+14.0067+47.99700 = 101.10200
A 2.26 M solution of KOH is prepared. Calculate the moles and mass of solute present in a 15.2-mL sample of this solution. The molar mass of KOH is 56.11 g/mol.
Answer:
0.0344 moles and 1.93g.
Explanation:
Molarity is defined as the ratio between moles of a solute (In this case, KOH), and the volume. With molarity and volume we can solve the moles of solute. With moles of solute we can find mass of the solute as follows:
Moles KOH:
15.2mL = 0.0152L * (2.26mol / L) = 0.0344moles
Mass KOH:
0.0344 moles * (56.11g/mol) = 1.93g of KOH
1
Give two reasons that show sugar is a compound
2
What is the difference between carbon (charcoal and suga? Compra ad 1
12. Which of these is a solution? *
Gold
Salt
Water
Carbonated Water
All of the above.
Answer:
carbonated water
remaining are single element
Do earthquakes occur at convergent plate boundaries?
Yes or no?
Answer:yes
Explanation:
what????????????????????????????????????????????????
Answer:
I
Explanation:
d
k
uhm....is there anything you need help with?
What type of compound is Sodium hydroxide?
A.acid
B.base
C.element
D.salt
Answer: B: Base
Explanation: I took the test
A certain chemical reaction releases of heat for each gram of reactant consumed. How can you calculate what mass of reactant will produce of heat
Answer:
Specific heat capacity formula
Explanation:
The heat capacity gives the exact heat energy at which a given mass of a substance is heated from one temperature to another.
This formula can help determine how much heat is gained or lost during the reaction and is given by:
Q = mcΔT
where:
Q = heat energy in Joules or Calories
m - mass of the substance (g)
c = Specific heat capacity (J/kg°C)
ΔT = change in temperature = (final temp - initial temp) (°C)
I hope this was helpful.
(1132 CHCH2CH = CH2
12. Give the complete IUPAC name for each of the following compounds:
(a) (CH3)2CHF
(b) CH3CHCICHCICH3
(C)
CH3CHCH;
CH2CH3
(d) CH3 CH2 CH = CHCHZ
(e)
CH3CH2CH2CHBCH2CH3
CH2CH=CH2
Answer:
Ok:
Explanation:
a) 2-fluoropropane
b) 2,3 dichlorobutane
c) pent-2-ene or 2 pentene (I assume the semicolon was a typo)
d) Same as c (I assume Z is a typo too)
e) non-1-ene or 1-nonene (I assume the B is a 2)
Which lists important roles of coral reefs?
cleaning oil from oceans, protecting beaches, producing oxygen
producing oxygen, offering medical benefits to humans, supporting a variety of organisms
supporting a variety of organisms, cleaning oil from oceans, producing oxygen
offering medical benefits to humans, protecting beaches, supporting a variety of organisms
Answer:
D. offering medical benefits to humans, protecting beaches, supporting a variety of organisms
Explanation:
I took the test and put C and got it wrong and l went back to see what the correct answer as and it was D.
The reaction where sodium (Na) reacts with water to produce hydrogen gas is a type of reaction.
Answer:
In what way and in what form does sodium react with water? A colourless solution is formed, consisting of strongly alkalic sodium hydroxide (caustic soda) and hydrogen gas. This is an exothermic reaction.
Investigate: Press Reset. Start with 2.000 moles of sulfur, then press Start. How many atoms do you think this amount represents
Answer:
1.204428 * 10^24 atoms
Explanation:
Number of moles = 2 mol
Number of atoms = ?
The relationship between moles and atoms is given by the avogadro's umber. This is the number of units in one mole of a substance. The units can be atoms, ions etc In this case it is atoms. The number is equal to 6.02214076 * 10^23
This means;
1 mol = 6.02214076 * 10^23
2 mol = x
Upon solving for x,
x = 2 * 6.02214076 * 10^23
x = 12.04428 * 10^23
x = 1.204428 * 10^24 atoms
I need a answer ASAP
Answer:
3.2 millions years oldExplanation:
i hope it helps :)
what is the volume of the rock? if the water rose from 50L to 70mL
Find the volume, in Liters, of 2.5 x 1024 molecules of chlorine gas at STP.
Answer:
V = 93.0 L
Explanation:
Hello!
In this case, when computing the PVT properties for an ideal gas, we need to use the following equation:
[tex]PV=nRT[/tex]
In such a way, for 2.5 x 10²⁴ molecules of chlorine at STP (273.15 K and 1.00 atm) we first need the moles based on the Avogadro's number:
[tex]n = 2.5x10^{24}molec*\frac{1mol}{6.022x10^{23}molec} = 4.15mol[/tex]
Now, we solve for volume on the ideal gas equation to obtain:
[tex]V=\frac{nRT}{P}[/tex]
So we plug in and get:
[tex]V=\frac{4.15mol**0.08206\frac{atm*L}{mol*K}*273.15K}{1.00atm}\\\\V=93.0L[/tex]
Best regards!
What do tissues combine to form?
A. organisms
B. cells
C.organ systems
D. organs
What kind of ions does metal form?
* ionic bond
* covalent bond
* anions
* cations
* melting point
* boiling point
conductivity
* Polyatomic Ions
* Valence electron
* Metal
* Nonmetal
* Metaloids
Answer:
Option D: Cations
Explanation:
Have a great day.
Suppose you wanted to dissolve 40.0 g NaOH in enough H2O to make 6.00 dm3 of solution
Molarity of solution = 1.6 M
Further explanationGiven
40 g NaOH
6 L solution
Required
Steps to solve the problem of molarity
Solution
No additional information about the question.
If you want to make the solution above, then we just need to put the existing NaOH (40 g) into 6 L of water, then do the stirring (in a warm temperature above the hot plate will speed up the NaOH dissolving process)
But if you want to know the molarity of a solution, then
1. we calculate the moles of NaOH[tex]\tt mol=\dfrac{mass}{MW}[/tex]
MW(molecular weight) of NaOH=
Ar Na+ Ar O + Ar H
23 + 16 + 1 = 40 g/mol
so mol NaOH :
[tex]\tt mol=\dfrac{40~g}{40~g/mol}=1~mol[/tex]
2. Molarity(M)[tex]\tt M=\dfrac{n}{V}\\\\M=\dfrac{1}{6}\\\\M=0.16[/tex]
Give the IUPAC name for each compound.
Answer:
a. 1-fluoro-3,3,4-trimethyl-pentane.
b. 1-iodo-3-ethyl-2-methyl-hexane.
c. 1,3-dichloro-5-dimethyl-hexane.
d. 1-bromo-3-methyl-cyclopentane.
Explanation:
Hello!
In this case, according to the IUPAC rules for the listed alkyl halides, we first need to name the halogens (considering periodic order) then alkyl radicals and finally the parent chain; thus, the names are given below:
a. 1-fluoro-3,3,4-trimethyl-pentane.
b. 1-iodo-3-ethyl-2-methyl-hexane.
c. 1,3-dichloro-5-dimethyl-hexane.
d. 1-bromo-3-methyl-cyclopentane.
e. 5-chloro-1-bromo-1,1,5-trimethyl-pentane (radicals are not clear).
Best regards!
Fungus is an example of a/an-
A:tissue
B:cell type
C:organ
D:organism
Answer:
D.organism
Explanation:
A fungus from the kingdom fungi is an organism
Answer:
D. organism
......................
How many electrons would Fluorine have to gain or lose to become stable?
Answer:
is most likely to gain one electron to form an ion with a 1- charge.
Identify the products in the following chemical reaction: Multiply chose
2NaHCO3 + CaCl2 → CaCO3 + CO2 + 2NaCl + H2O
A. NaHCO3
B. CaCl2
C. CaCO3
D. CO2
E. NaCl
H2O
Answer:
C. CaCO3
D. CO2
E. NaCl
. H2O
what type of molecule are these and what is the strongest IMFs in between?
Answer:
CH2O is formaldehyde a covalent compound and its intermolecular forces are week
KCl is an ionic compound formed by electrostatic force of attraction between positive and negative charge. Ionic compounds also exists in three dimensional crystal lattic that is why intermolecular forces in KCl is stronger.
Moreover melting point of KCl is higher than CH2O
Explanation:
how are series and parallel circuits the same?
What is the definition of climate?
1) An area's long term weather pattern
2)When large air masses of different density, moisture, and temperature mee
3)The state of the atmosphere at a given place and time
4)Large volume of air that has similar characteristics of temperature and water
vapor content
Answer:
1) An area's long term weather pattern
Explanation:
Climate is defined as the weather pattern in an area for the long term. Climate means the usual condition of the humidity, temperature, wind, rainfall, and atmospheric pressure in the surface area of Earth for the long term. Usually the time period for a climate in a region is taken over 30-years.
Weather is the state of the atmosphere and climate the long-term weather pattern of the area. For example: degree to which it is hot or cold is weather and expect snow in the Northeast in every January is climate.
Hence, the correct answer is "1) An area's long term weather pattern".
How can you use density to separate mixtures like sand and small plastic pellets?
Answer:
Slide a magnet through the mixture. When you take the magnet off, the iron filings are going to be attracted to the magnet and the sand will stay in the bowl
Explanation:
Answer:
Density can be used to separate the substances that make up a mixture, because each substance in a mixture has its own density. For example, if a mixture of sand and oil is placed in water, the sand will sink to the bottom of the container. The sand is more dense than the water.
Explanation:
Please mark me as brainy if this helps