Answer:
Radium
Explanation:
Radium is a radioactive element which was often put in beauty products.
You have a big bon fire outside in your back yard . Although it is only 40 degrees F, you and your friends are all warm sitting by the fire. This is
Question 14 options:
An exothermic exchange from radiant energy.
An endothermic exchange from conduction.
An exothermic exchange by conduction.
None of the above are correct
Answer:
An exothermic exchange by conduction
Explanation:
Because the heating system (the bonfire) is what is conducting the energy, and is transferring said energy to it’s surroundings, this is an exothermic exchange.
pls help AHHHHHHHHHHHH
Answer:
1 Zn + 2 HCl ⇒ 1 H₂ + 1 ZnCl₂
Hope this helps!!!
The most common source of copper (cu) is the mineral chalcopyrite (cufes2). How many kilograms of chalcopyrite must be mined to obtain 500. G of pure cu?
The amount of chalcopyrite must be mined to obtain 500g of pure Cu is 1.4 kilograms.
What is the relation between mass & moles?Relation between the mass and moles of any substance will be represented as:
n = W/M, where
W = given massM = molar massMoles of Cu = 500g / 63.5g/mol = 7.87 mole
Given chemical reaction is:
CuFeS₂ → Cu²⁺ + Fe²⁺ + 2S²⁻
From the stoichiometry of the reaction, it is clear that
1 mole of Cu = produced by 1 mole of CuFeS₂
7.87 mole of Cu = produced by 7.87 mole of CuFeS₂
Mass of given moles of CuFeS₂ = (7.87mol)(183.5g/mol) = 1,444.14g = 1.4kg
Hence required mass of CuFeS₂ is 1.4 kg.
To know more about mass & moles, visit the below link:
https://brainly.com/question/20838755
#SPJ4
what is the best definition of weight
A solution of 5 m hci is already made. you need to dilute the solution to 1 m hci. the 1 m hci solution is _____
options :slower, stronger, weaker, faster ,
1M HCl solution is weaker
4. An element is a substance made up of two kinds of matter. True or false?
A. true
B. false
Answer:
false
Explanation:
Elements are pure substance. A ball of sodium will only have sodium atoms.
a solution with an [OH-] concentration of 1.20 x 10-7M has a pOH and pH of?
Taking into account the definition of pH and pOH, the solution has a pOH of 6.92 and a pH of 7.08.
Definition of pHpH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:
pH= - log [H⁺]= - log [H₃O⁺]
Definition of pOHSimilarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
Relationship between pH and pOHThe following relationship can be established between pH and pOH:
pOH + pH= 14
pOH and pH in this caseA solution has an [OH⁻] concentration of 1.20×10⁻⁷ M. Replacing in the definition of pOH:
pOH= - log (1.20×10⁻⁷ M)
Solving
pOH= 6.92
Then, pH is calculated as:
pH + 6.92= 14
pH= 14 - 6.92
pH= 7.08
Finally, the solution has a pOH of 6.92 and a pH of 7.08.
Learn more about pH and pOH:
brainly.com/question/16032912?referrer=searchResults
brainly.com/question/13557815?referrer=searchResults
#SPJ1
Which conclusion is supported by the information in the graph?
Timed!!! 56 minutes left!!!!
The cost of producing a kilowatt of power with a fuel cell will be less than $30 in 2015.
Fuel cell cars are unlikely to be affordable in the near future.
The rate of emissions is decreasing because of inexpensive fuel cell technology.
The environment is unlikely to improve as a result of cheap fuel cell technology.
Answer:
A. The cost of producing a kilowatt of power with fuel cell will be less than $30 in 2015
Definition: The time in an age-structure diagram where the population is not yet reproducing.
Answer:
Explanation:An age-structure diagram provides a snapshot of the current population and can represent information about the past and give potential clues about future problems. When you are interpreting age-structure diagrams, it is important to compare the width of the base to the rest of the population
Diethyl ether has a δhvap of 29. 1 kj/mol and a vapor pressure of 0. 703 atm at 25. 0°c. What is its vapor pressure at 76. 0°c?
The heat of vaporization is the heat required to turn 1 gm solid into a liquid. The vapor pressure of diethyl ether at 76 degrees celsius is 1.95 atm.
What is vapor pressure?Vapour pressure is the pressure exerted by the vapors of the equilibrium system. Clausius-Clapeyron equation is used to find the vapor pressure.
[tex]\rm ln \dfrac{P_{2}}{P_{1}} = \rm \dfrac{\delta H}{R} (\dfrac{1}{T_{1}} - \dfrac{1}{T_{2}})[/tex]
Given,
Initial pressure = 0. 703 atm
Initial temperature = 298K
Final temperature = 349 K
Change in enthalpy of vaporization = 29100J/mol
Boltzman constant = 8.314 J/K mol
Substituting values above:
[tex]\begin{aligned} \rm ln \dfrac{P_{2}}{P_{1}} & = \rm \dfrac{\delta H}{R} (\dfrac{1}{T_{1}} - \dfrac{1}{T_{2}})\\\\&= \dfrac{9100}{8.314}(0.0004903)\\\\&= 0.5363\end{aligned}[/tex]
Solving further,
[tex]\begin{aligned} \rm ln \dfrac{P_{2}}{0.703} &= 0.5363\\\\& = \rm e^{0.5363}\\\\&= 1.70\end{aligned}[/tex]
The final pressure is calculated as:
[tex]\rm P_{2} = (0.703 atm)(1.70) = 1.95\;\rm atm[/tex]
Therefore, the vapor pressure at 76 degrees celsius is 1.95 atm.
Learn more about vapor pressure here:
https://brainly.com/question/14615211
#SPJ4
paragraph about what has caused co2 levels to rise / will give brainliest
Answer: We may only emit about 4% of total emissions, while the natural environment emits the other 96%. But the thing is the natural environment adds and takes out CO2 from the system in roughly equal amounts (at least in the short and medium term). We only add it. We are adding so much of it that the environment can only absorb about half of it, thus the rapid increase in CO2 levels, thus the rapid increase in temperatures.
Explanation:
when a solid will not dissolve in a liquid, it is termed___
a. insoluble
b. miscible
c. soluble
d. dissolvable
Answer:
a. insoluble.
Explanation:
This is the opposite of soluble, which means things can dissolve in a liquid, so insoluble means a solid cannot dissolve in a liquid.
Brainliest will really help me!
Which statement is true based on the diagram?
A.sulfate ions will move from right to left through the salt bridge
B.sulfate ions will move from left to right through the wire
C.sulfate ions will move from left to right through the salt bridge
D.sulfate ions will move from right to left through the wire
Sulfate ions will move from left to right through the salt bridge. The salt bridge allows the passage of ions between solutions.
What is an electrochemical cell?An electrochemical cell is a cell where electrical energy is produced as a result of chemical reactions.
We have to note that the anions tend to move from the cathode to the anode hence, sulfate ions will move from left to right through the salt bridge.
Learn more about electrochemical cell:https://brainly.com/question/12034258
#SPJ1
__________ happens when no particles or atoms can move anymore due to the lack of heat
Freezing Point
Absolute Zero
The Ice Theory of 83
Radiation
Absolute Zero happens when no particles or atoms can move anymore due to the lack of heat. Option A.
What is Absolute Zero temperature?Generally, Absolute zero is simply the moment at which all of the atoms have totally halted relatively to each other.
In conclusion, Absolute Zero occurs when no particles or atoms can move owing to a lack of heat.
Read more about Temperature
https://brainly.com/question/13439286
#SPJ1
What does an embryo do in a seed
Answer:
The embryo, endosperm, and seed coat are the three major parts of a seed. An embryo is the young multicellular organism formed before it emerges from the seed. A seed is an embryonic plant, which stores food and is enclosed in a protective outer covering, which give rise to a new plant.
Braconid wasps lay eggs on the tomato hornworm caterpillar's body. The larvae that hatch from the eggs start feeding on the tissue of the caterpillar. What type of ecological relationship do both the organisms share?
Answer:
Braconid wasps lay eggs on the tomato hornworm caterpillar's body. The larvae that hatch from the eggs start feeding on the tissue of the caterpillar. What type of ecological relationship do both the organisms share?
ANSWER FAST!!
An experiment requires a solution that is 80% ethyl alcohol by volume. What volume of ethyl alcohol should be added to 400 mL of water to make this solution?
Answer: 800 mL of methyl alcohol should be added to 200 ml of water to make this solution.
Explanation:
Volume of the methyl alcohol = x
Volume of water = y = 200 mL
Volume of the solution ,V = x + y
Volume percentage of solution = 80%
x = 800 mL
800 mL of methyl alcohol should be added to 200 ml of water to make this solution.
What is the empirical formula of a compound containing 90 g carbon 11 g hydrogen and 35 g nitrogen
The empirical formula of the compound containing 90 g carbon, 11 g hydrogen and 35 g nitrogen is C₆H₉N₂
Data obtained from the questionCarbon = 90 gHydrogen = 11 gNitrogen = 35 gEmpirical formula = ?How to determine the empirical formulaDivide by their molar mass
C = 90 / 12 = 7.5
H = 11 / 1 = 11
N = 35 / 14 = 2.5
Divide by the smallest
C = 7.5 / 2.5 = 3
H = 11 / 2.5 = 4.4
N = 2.5 / 2.5 = 1
Multiply by 2
C = 3 × 2 = 6
H = 4.4 × 2 ≈ 9
N = 1 × 2 = 2
Thus, the empirical formula of the compound is C₆H₉N₂
Learn more about empirical formula:
https://brainly.com/question/24297883
#SPJ1
What is the mass of 22.4 L of Cl2 at STP? (5 points) a 35.45 grams b 70.9 grams c 22.4 grams d 28.01 grams
Answer: 70.9 grams
Explanation:
22.4 L is about 1 mole, meaning that we need to find the mass of 1 mole of chlorine gas, which is about 70.9 grams.
*
Determine the electronegativity difference (AEN) and the type of bond formed
(ionic, polar, non-polar).
BaCl2
Nyour answer
the electronegativity difference (AEN):
<0.5: covalent (non polar)
0.5- 1.7: covalent (polar)
> 1.7 : ionic
BaCl₂
Ba = 0.9
Cl = 3
Cl - B = 3 - 0.9 = 2.1 (ionic)
16. What part of the atom does radioactivity involve?
O Outer energy shells
Nucleus
O Entire atom
Inner energy shells
Answer:
inner energy shells are involved in radioactive activity
Answer: I think its NUCLEUS
Explanation: Good luck yall
what does doping mean ?
give an example.
[tex] \\ [/tex]
ty! ~
D∅ping is usually used in sports to refer to the act of taking substances that enhance performances.
What is d∅ping?D∅ping refers to the act of taking substances that are banned in sports.
The word is usually used with respect to sporting events. Certain substances have been found to give athletes a performance advantage over their competitors. These are referred to as d∅pes and are usually banned in most sports.
When a sportsperson takes any of these banned substances, they are said to have d∅ped.
For example, an athlete anabolic steroids before taking part in a sporting event.
More on d∅ping can be found here: https://brainly.com/question/11706474
#SPJ1
Doping = use of drugs to improve athletic performance.
Doping means taking of some drugs that enhance athletic performance. Many players use doping to enhance their performance. It is illegal, and it is banned. If any player caught doing this, he/she might be suspended for years.
Hope it help you
which of the following enthalpy diagrams represent exothermic reactions? Endothermic reactions? please state which one each diagram is.
Answer:
a,c and d are exothermic
b is the endothermic
Explanation:
exothermic because energy required to form products is less than the energy required to break bonds in reactants.
endothermic because energy required to form products is larger than the energy required to break bonds in reactants.
Which substance is a mixture of two or more metals?.
The substance which is mixture of two or more than two metals is called as alloy. Alloy is metallic mixture of any elements.
What is alloy ?Alloy is the mixture of two or more than two metal . This mixture may be homogenous or heterogenous ,in both of the phase alloy mixture occur. It may be solid or mixture of many phases.
Alloy are classified into two parts i.e. substitutional alloy and interstitial alloy. An example of alloy is red gold which is the mixture of copper and gold. and there is mixture of silver and gold to make an alloy.
There are different types of alloy present in environment like nickel alloy, zinc alloy, bronze alloy , stainless steel alloy. I an alloy contain ferrous metal it will be rust.
Thus, Alloy is the mixture of two or more than two elements.
To learn more about alloy follow the link below;
https://brainly.com/question/2533907
#SPJ6
A 10.00-mL sample of HCI solution was transferred to an Erlenmeyer flask and diluted by adding about 40 mL of distilled water. Phenolphthalein indicator was added, and the solution was titrated with 0.215 M NaOH until the indicator just turned pink. The exact volume of NaOH required was 22.75 mL. Calculate the concentration of HCI in the original 10.00-mL sample.
Use Relationship between C and V
C1V1=C2V2(40-10)C1=22.75(0.215)30C1=4.9C1=4.9/30C1=0.1634MWhere on the periodic table is a metal element most likely found? Do not think about the stair case split.
bottom
right side
middle
Answer:
C.) Middle
Explanation:
A.) is incorrect because elements on the bottom of the periodic table can be metals, nonmetals, or metalloids. However, the majority of these elements would be metals.
B.) is incorrect because elements on the right side (aka. the p-block) of the periodic table are mostly nonmetals. This excluding the stair case elements which are metalloids and elements to the left of the stair case which are metals.
C.) is correct because elements located in the middle of the periodic table (aka. the d-block) are always metals. The elements in this section are usually nicknamed the "transition metals". It should be noted that elements on the left side (aka. the s-block) of the periodic table are also metals (excluding hydrogen).
Most lakes have rivers flowing out of them, carrying water to the ocean. However, some lakes, including the Great Salt Lake and the Dead Sea, have no outlet. Water flowing into these lakes leaves only through evaporation. Considering that the water flowing into the lakes contains many dissolved substances, how does the lack of an outlet affect the composition of these lakes? What would you expect to happen after many more years of inflow and evaporation?
The lack of an outlet will affect the composition of these lakes by causing an accumulation of organic and inorganic nutrients due to decomposition of living materials.
What is a lake?Lake is a small stream of running water or a channel for water.
Lakes are usually a standing body of water or slow moving. This means that some lakes, including the Great Salt Lake and the Dead Sea, have no outlet.
The lack of an outlet will affect the composition of these lakes by causing an accumulation of organic and inorganic nutrients due to decomposition of living materials.
Learn more about lakes at: https://brainly.com/question/858802
#SPJ1
2S+3O2=2SO3. If 4moles of sulfur reacts with 9. 5 moles of oxygen, how many moles of oxygen would remain after the reaction?
Answer: 3.5 moles
Explanation:
For every 2 moles of sulfur consumed, there are 3 moles of oxygen consumed.
This means that sulfur is the limiting reactant, meaning that 2(3)=6 moles of oxygen will be consumed.
Thus, 9.5-6=3.5 moles of oxygen will remain.
Name these compounds according to IUPAC.
The IUPAC names of the compound 8 is propional and compound 9 is propanone or ethyl methyl ketone.
What is IUPAC name?International Union of Pure and Applied Chemistry, IUPAC, is naming of the organic compound by the rules of chemistry.
There are some rules, like identifying the functional group, to find the longest carbon chain.
Thus, the IUPAC names of the compound 8 is propional and compound 9 is propanone or ethyl methyl ketone.
Learn more about IUPAC name
https://brainly.com/question/16631447
#SPJ1
Which of these best describes electrolysis?
A. another name for all chemical reactions
B. a term that refers to the division of hydrogen and oxygen atoms
C. a reaction that occurs when an electric current passes through water
D. a reaction that occurs any time an electric current is introduced to a solid
Answer:
c
Explanation:
chemical decomposition produced by passing an electric current through a liquid or solution containing ions.
