By what process does thorium-230 decay to radium-226?.
Answer:
alpha emission
Explanation:
How do elements differ going from left to right across a period on the periodic table?
please choose one
They become more valuable.
They become lighter.
They become more radioactive.
Their atomic number increases.
a gas has a temperature of 14C, and a volume of 4.5 liters. if the temperature is raised to 29C and the pressure is not changed, what is the new volume of the gas?
Answer: 4.7 L
Explanation:
A student dissolves 15 grams
of salt in 250 mL of water.
What is the solute? What is
the solvent?
Answer:
salt is solute,water solvent, the mixture is the solition.
A student dissolves 15 grams of salt in 250 mL of water. The solute is salt and the solvent is water.
What is a solution?A solution is a homogeneous mixture of one or more solutes dissolved in a solvent.
solvent: the substance in which a solute dissolves to produce a homogeneous mixturesolute: the substance that dissolves in a solvent to produce a homogeneous mixtureFor solutions with components in the same phase, the substances present in lower concentration are solutes, while the substance present in highest abundance is the solvent.
Therefore, A student dissolves 15 grams of salt in 250 mL of water. The solute is salt and the solvent is water.
Learn more about Solutions, here:
https://brainly.com/question/30665317
#SPJ3
What is the atomic symbol for an isotope with protons = 27 and atomic mass = 60?
Answer:
Cobalt (Co)
Explanation:
it has 27 protons and atomic mass of 60 in Cobalt 60 isotope
a balloon is filled with 2 liters of air at sea level, then a scuba diver carries it under the ocean. if the scuba diver stops when the pressure on the balloon is 3 atmospheres, what is the new volume of the balloon? round to the nearest hundredth.
A. 0.67 liters
B. 1.5 liters
C. 6 liters
D. 5 liters
Answer:
The correct answer is C. 6 Liters
Explanation:
You have to multiply the 2 liters by the atmospheres (which is 3) you get 6. six liters is the new volume.
It required 25.0 mL of 0.333 M NaOH solution to completely neutralize 15.0 11 mL of HCl solution. What was the molarity of the HCI? *
0.555 M
0.200 M
1.11 M
0.277 M
Answer:
A
Explanation:
HCl and NaOH is a strong acid and strong base, respectively, and hence dissociates completely and reacts to form water:
[tex]\displaystyle \text{H}_\text{(aq)}^+ + \text{OH}_\text{(aq)}^- \longrightarrow \text{H$_2$O}_\text{($\ell$)}[/tex]
We are given that 25.0 mL of 0.333 M NaOH was used to neutralize 15.0 mL of HCl.
Convert from moles of NaOH used to moles of HCl reacted:
[tex]\displaystyle \begin{aligned} 25.0\text{ mL} & \cdot \frac{0.333\text{ mol NaOH}}{1\text{ L}} \cdot \frac{1\text{ L}}{1000\text{ mL}} \cdot \frac{1\text{ mol OH}^-}{1\text{ mol NaOH}}\cdot \\ \\ & \cdot\frac{1\text{ mol H}^+}{1\text{ mol OH}^-} \cdot \frac{1\text{ mol HCl}}{1\text{ mol H}^+}\\ \\ & = 8.33\times 10^{-3}\text{ mol HCl}\end{aligned}[/tex]
Therefore, the molarity of the original HCl solution is:
[tex]\displaystyle \begin{aligned} \ [\text{HCl}] & = \frac{\text{ mol HCl}}{\text{L soln.}} \\ \\ & =\frac{8.33\times 10^{-3}\text{ mol HCl}}{15.0\text{ mL}} \cdot \frac{1000\text{ mL}}{1\text{ L}} \\ \\ & = 0.555\text{ M}\end{aligned}[/tex]
In conclusion, our answer is A.
Mosquitoes are responsible for transmitting the zika virus. In this case, the mosquitoes are
the disease.
asymptomatic transmitters.
biological vectors.
pathogens.
active carriers.
Answer:
active carriers
Explanation:
Mosquitoes are responsible for transmitting the zika virus. In this case, the mosquitoes are active carriers
Answer:
E -- active carriers
Explanation:
the mosquitos would be active carriers...
Hope this helps! Please let me know if you need more help or think my answer is incorrect. Brainliest would be MUCH appreciated. Also remember to rate answers to help other students, While leaving thanks to answers that help you. Have a great day!
10. What is a battery an example of?
a. load b. switch c. energy source d. conductor
Answer:
an energy source
Explanation:
27.2g CuCl2 was dissolved in 2.50 L of the water. What is the molality of the solution?
Answer:
0.0800 (on CK-12)
Explanation:
Given grams of CuCl2/molar mass of CuCl2
27.2g/134.45g=0.2023...
Next,
0.2023mol/2.50L = 0.0800
The molality of the copper(II) chloride (CuCl₂) solution is 0.081 mol/kg
MolalityMolality is a measure of the number of moles of solute in a solution corresponding to 1 kg or 1000 g of solvent
First, we will determine the number of moles of CuCl₂ present
Using the formula,
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass}[/tex]
Mass of CuCl₂ = 27.2 g
Molar mass of CuCl₂ = 134.45 g/mol
∴ Number of moles of CuCl₂ present = [tex]\frac{27.2}{134.45 }[/tex]
Number of moles of CuCl₂ present = 0.2023 mole
Now, for the molality of the solution
Volume of solvent (water) = 2.50 L
Since the density of water = 1kg/L
Then, mass of the solvent (water) = 2.50 kg
[tex]Molality = \frac{Number\ of\ moles}{Mass\ of\ solvent}[/tex]
∴ Molality of the solution = [tex]\frac{0.2023}{2.50}[/tex]
Molality of the solution = 0.081 mol/kg
Hence, the molality of the solution is 0.081 mol/kg
Learn more on Calculating molality here: https://brainly.com/question/12323213
#SPJ2
Given bh3, o3, co2, and nh3, which of these compound is an exception to the octet rules?.
Answer:
a. BH₃
Explanation:
According to the octet rules, atoms reach stability when are surrounded by eight electrons in their valence shell when they combine to form a chemical compound.
From the options, the only compound in which the central atom does not meet the octet rules is BH₃. The central atom is boron (B), which has 3 electrons in its valence shell. When B is combined with hydrogen (H), 3 electrons from the 3 atoms of H are added. The total amount of electrons is 6, fewer than 8 electrons needed to meet the rule.
hope this helps
Why Do Onions Make You Cry? Even better, know how to prevent the tears.
Answer:
The onion cells release compounds into the air, and enzymes must follow up to alter amino acids into other compounds, causing irritation in the eye. To prevent, "crying" from an onion, try peeling the onion, then chilling the onion in the fridge for about 30 minutes. Otherwise, you can buy tearless onions.
Which economical systems do you most agree with and why
Answer:
be specific it's too little information
Complete the following calculations regarding acid/base titrations
If 25.5 mL of a 0.1 M base solution was required to ti trate 60 mal of an unknown acid solution,what is the molarity of the acid solution?
Based on the information provided and the assumption that the mole ratio of the acid to the base is 1:1, the molarity of the acid would be 0.0425 M
Acid/base TitrationUsing the equation:
CaVa = CbVb
This is based on the assumption that the stoichiometric mole ratio of the acid to the base is 1:1.
Ca = CbVb/Va
0.1 x 25.5/60 = 0.0425 M
More on acid/base titration can be found here: https://brainly.com/question/2728613
Why is the number of hydrogen atoms and oxygen atoms the same in both the reactants and the products?
Answer:
The law of conservation of matter says that matter cannot be created or destroyed.
Explanation:
Answer:
Atoms don’t appear or disappear during the reaction. Instead, they get rearranged.
Explanation:
Edmentum answer
A current of 3.46 A is passed through a Sn(NO3)2 solution for 1.40 h . How much tin is plated out of the solution?
Answer:
About 10.7 grams.
Explanation:
The reduction reaction is represented by:
[tex]\displaystyle \text{Sn}^{2+}_\text{(aq)} + 2e^- \longrightarrow \text{Sn}_\text{(s)}[/tex]
A current of 3.46 amperes (C/s) is passed through the solution for 1.40 hours. The total amount of charge is hence:
[tex]\displaystyle 1.40\text{ hour} \cdot \frac{3600\text{ s}}{1\text{ hour}}\cdot \frac{3.46\text{ C}}{1\text{ s}} = 1.74\times 10^4\text{ C}[/tex]
One mole of solid Sn is transferred per two moles of electrons. Hence, using Faraday's constant:
[tex]\displaystyle 1.74\times 10^4\text{ C} \cdot \frac{1\text{ mol e$^-$}}{96485\text{ C}} \cdot \frac{1\text{ Sn}}{2\text{ mol e$^-$}}\cdot \frac{118.71\text{ g Sn}}{1\text{ mol Sn}} = 10.7\text{ g Sn}[/tex]
In conclusion, about 10.7 grams of tin is plated out of the solution.
Which of the following happens when a reaction reaches dynamic equilibrium in a closed system?
The concentrations of the reactants and products increase.
The concentrations of the reactants and products decrease.
The rate of the forward reaction equals the rate of the reverse reaction.
The rate of the forward reaction is slower than the rate of the reverse reaction.
Answer:
Option C
Explanation:
At equilibrium the reaction remains constantThe rate of forward reaction equals rate if backward reactionConcentration of products and reactants remains sameAnswer:
The rate of the forward reaction equals the rate of the reverse reaction.
Explanation:
Why does an aqueous solution of an ionic substance conduct an electric current?.
Answer:
Because ions in an aqueous solution are free to move independently from each other. the net flow of cations toward a negative or positive electrode results in a flow of charge, which is an electrical current.
Explanation:
As ocean water salt concentration increases, the _____.
Question 1 options:
water density increases and rises to the top of the sea.
water density increases and sinks to the bottom of the sea.
water density decreases and rises to the top of the sea.
water density decreases and sinks to the bottom of the sea.
Answer:
B water density increases and rises to the top of the sea
Explanation:
i took a test and got it correct lol
Which of these involves the formation of a new chemical substance?
Select one:
a. evaporation of gasoline
b. mixing salt and pepper
C. dissolving sugar in tea
d. rusting of an iron chain
Which of these involves the formation of a new chemical substance?
a. evaporation of gasoline
b. mixing salt and pepper
c. dissolving sugar in tea
d. rusting of an iron chain
[tex] \\ [/tex]
Answer:D. Rusting of an iron chain[tex]__________[/tex]
A. Evaporation of gasoline
It does not form any chemical substance. Evaporation, is part of a physical change. Physical change only changes in its physical characteristics. Evaporation changes from liquid, to gas. Therefore, it is a physical change.B. Mixing salt and pepper
No new substance formed. It does not form any chemical substance nor chemical change. When you mix salt and pepper, it only is a mixture wherein no new material can be form. Therefore, this is physical change as well.C. Dissolving sugar in tea
When you dissolve sugar in your tea, it only changes the taste of the tea to sweet. Taste is part of the characteristic of physical change. It does not form any chemical substance nor chemical change. Therefore, this is physical change.D. Rusting of an iron chain
Rusting is one of the common examples of chemical change in our daily lives. Rust is the new substance formed. However, this is considered as chemical change because this is irreversible or cannot be returned to its original substance/material. Finally, rusting of an iron chain involves the formation of new chemical substance.Hence, the answer is D. Rusting of an iron chain.
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation: ()zn ()hcl → ()zncl2 ()h2
Based on the chemical equation, to balance the given equation we should use 2 as a coefficients of HCl on reacatnt side of the reaction.
What is balanced equation?Balanced chemical equations are those equation in which each entities are present in same amount on reactant side as well as on the product side of the chemical reaction.
Given chemical reaction is:
Zn + HCl → ZnCl₂ + H₂
In the above reaction equation is not balanced as number of chlorine and hydrogen atoms are not equal on both sides, so balanced equation will be:
Zn + 2HCl → ZnCl₂ + H₂
Hence we add 2 as a coefficient of HCl to balance the equation.
To know more about balance equation, visit the below link:
https://brainly.com/question/15355912
Answer:
1 2 1 1
Explanation:
If 25 mL of a 1 M HI solution is added to 25 mL of a 1 M KOH solution, the resulting solution would be
The reaction equation is:
HI(aq) + KOH(aq) → KI(aq) + H2O
1 mol HI reacts with 1 mol KOH
In your problem you have:
Mol HI in 10 mL of 1M solution = 10mL/ 1000 mL/L * 1 mol /L = 0.01 mol HI
Mol KOH in 5 mL of 1 M solution = 5 mL / 1000 mL/L * 1 mol /L = 0.005 mol HI
The 0.005 mol of KOH will neutralise 0.005 mol of HI - leaving 0.005 mol HI unreacted in 15 mL solution
This solution will be acidic
I guess that that answers your question - But you may be interested in calculating the pH of the solution
Have a great day!
how do you find the change in enthalpy on a potential energy diagram HELP MEEEE
LOL... I don't think my beautiful drawing helps a ton.
But basically in a potential energy diagram, the height distance between the reactants and products is the ∆H, aka the enthalpy change.
If the reactants are higher than products, then the reaction is exothermic.
If the products are higher than reactants, then the reaction is endothermic.
REEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
Answer:
c. sun, radiation
Explanation:
What is the volume, in liters, of 12 moles of a gas at a temperature of 467.5 K at a pressure of 9.67 atmospheres?
P
V
=
n
R
T
R = 0.0821
a
t
m
⋅
L
m
o
l
⋅
K
Explanation:
From PV = nRT
9.67V = 12(0.0821)(467.5)
V = 47.63 L
A student wants to test an unknown chemical solution. What test should they perform to determine whether the chemical is an acid or base?
Or
Courtney wants to test an unknown chemical solution. What test should Courtney perform to determine whether the chemical is an acid or base?
A.
Test the solution by testing its conductivity
B.
Test the solution by increasing its temperature.
C.
Test the solution by tasting it.
D.
Test the solution's pH by using litmus paper.
The answer is D for whoever looked this up
Answer: D
Explanation:
The litmus paper will help determine the pH, and thus if it is an acid or a base.
What is the origin of fahrenheit and centigrade temperature scales?.
Answer:
The 18th-century German physicist Daniel Gabriel Fahrenheit originally took as the zero of his scale the temperature of an equal ice-salt mixture
Explanation:
If 25.0 g of NH₃ and 45.0 g of O₂ react in the following reaction, what is the mass in grams of NO that will be formed?
4 NH₃ (g) + 5 O₂ (g) → 4 NO (g) + 6 H₂O (g)
Answer:
44.2 g NO
Explanation:
Question is posted elsewhere, be sure to search before posting to save yourself some time :)
Is 18 karat gold a homogeneous mixture or heterogeneous mixture?
Answer:
Gold is an element. That means that it is the same all the way through and in an ideal state of purity contains nothing but gold atoms. Therefore it is not a mixture. In such a case it is as close to a uniform solid solution as may be, so it will be an homogeneous mixture.
Explanation:
really hope this helps :)
15. What is the maximum pH an aqueous solution of 0.050 M Cu(NO3)2 can be adjusted to before a precipitate of Cu(OH)2 will form
The maximum pH an aqueous solution of 0.050 M Cu(NO3)2 is mathematically given as
pH=5.8
What is the maximum pH an aqueous solution of 0.050 M Cu(NO3)2 can be adjusted to before a precipitate of Cu(OH)2 will form?
Generally, the equation for the Chemical reaction is mathematically given as
Cu(OH)2----><---Cu^2 +2OH-
Therefore
s^2=1.0*10^{-19}
s=3.16*10^{=9}
{OH-}=2s=6.3*10^10^{-19}
{H+}=10^{-14}/OH
{H+}=1.58*10^{-6}
In conclusion
pH=-log(1.58*10^{-6}
pH=5.8
Read more about Chemical reaction
https://brainly.com/question/16416932