Answer:
It was the last element first discovered in nature, rather than by synthesis. Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and decays
What are homogeneous mixture and heterogeneous mixture ?
Explanation:
"A homogeneous mixture has the same proportions of its components throughout any given sample and is also referred to as a solution. Conversely, a heterogeneous mixture has components of which proportions vary throughout the sample."
- Wikipedia
To everyone who has exams today, I WISH YALL THE BEST OF LUCK!!!!
ありがとう私は本当にこの励ましが必要でした :)
Why is it important to use scientific notation when talking about our solar system
and galaxies?
Answer:
The main purpose for converting numbers into scientific notation is to make calculations with surpisingly large or small numbers less complicated. Since zeros are not used to place the decimal point, all of the digits in a number in scientific notation are meaningful and easier to read. Hope this helps!
Explanation:
Which is associated with low humidity? *
dry air
warm air
rainforest
coastal area
Answer:
A: dry air
Explanation:
Trust me this is right, I’m doing the exam rn and if its not right I will come back and edit this.
Answer:
guy above me is right
Explanation:
100% on quiz
help me pleaseeeeee
Answer:
Arthropod (3)
Annelids (2)
Cnidarians (1)
Echinoderms (4)
Explanations:
I hope all this helps if u don't understand it let me know.
Which component of solution is dissolving medium? a.solute b.solvent
Answer:
Solvent
Explanation:
Question 14 Multiple Choice Worth 2 points) If we have less power, we most likely have
A. the same amount of work being done over a shorter period of time
B.more work done over a shorter period of time
C. more work done over the same amount of time
D.the same amount of work being done over a longer period of time
Answer:
D.
Explanation:
makes most sense for this question. when you're using the same amount of power over a longer period–you're bound to have less of it over time.
Webb is testing samples of different elements. One sample is a dull, yellow solid that
breaks into powdery pieces when he hits it with a hammer. How should Webb classify
the yellow solid?
As a metal
As a nonmetal
As a gas
As a metalloid
Answer: it's nonmetal
Explanation: Sulfur has characteristics of nonmetals. It does not have luster, it cannot conduct electricity, and it is brittle. On the periodic table, sulfur is in group 16/VIA, in the third period. The group is called the oxygen group or the chalcogens.
Answer:
i dont know
Explanation:
10. Electromagnetic waves used to examine broken bones inside the body are called
The answer to your question are X-Rays.
We use this all the time when we have broken bones in our skeletal system!
Answer:
it would be x-rays
Explanation:
Help plz:))) I’ll mark u brainliest ASAP 10 points
The heat of vaporization of diethyl ether is . Calculate the change in entropy when of diethyl ether boils at . Be sure your answer contains a unit symbol. Round your answer to significant digits.
Answer:
[tex]\Delta S=900\frac{J}{K}[/tex]
Explanation:
Hello!
In this case, since the information is not missing, the following one will be used as it is found on similar problems:
[tex]\Delta h=26.7kJ/mol\\T_b=34.6\°C\\m=769.0g[/tex]
In such a way, we use the following equation to compute the entropy:
[tex]\Delta S=\frac{n\Delta h}{T_b}[/tex]
Whereas n (moles) are computed by using its molar mass (74.14 g/mol) as follows:
[tex]n=769.0g*\frac{1mol}{74.14g}=10.4mol[/tex]
[tex]\Delta S=\frac{10.4mol*26.7\frac{kJ}{ml} }{(34.6+273.15)K}\\\\\Delta S=0.900 \frac{kJ}{K} \\\\\Delta S=900\frac{J}{K}[/tex]
Best regards!
500 grams of an unknown substance gains 23000 J of heat as it is heated from a temperature of 250C to 1250C. Using mathematical computation and the chart below, determine the identity of the unknown substance.
Answer:
The given substance is cast iron.
Explanation:
Given data:
Mass of substance = 50 g
Heat absorbed = 23000 J
Initial temperature = 250°C
Final temperature = 1250°C
Which metal is this = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 1250°C - 250°C
ΔT = 1000°C
23000 j = 50 g ×c ×1000 °C
23000 J = 50,000 g. °C×c
c = 23000 J /50,000 g. °C
c = 0.46 J/g.°C
The given substance is cast iron.
The cell membrane around a cell forms a barrier that protects and regulates the cell. Certain chemicals can pass through the plasma membrane because they have similar chemical properties as the membrane.
Which best describes those that can pass through?
They are concentrated.
They are soluble.
They are diluted.
They are heated.
Answer:
it is b (they are soluble)
Explanation:
got it right on edg and on quizlet
Answer:
B. They are soluble
Explanation:
You have 0.672 L of 4.78 M aqueous AlCl3 solution in a glass. If you gently heat the solution until only 0.380 L is left, what is the new molarity of the AlCl3 solution?
Answer:
8.45 M
Explanation:
To solve this problem we need to keep in mind the definition of molarity:
Molarity = moles / volumeFirst we calculate the moles of AlCl₃ in 0.672 L of a 4.78 M solution:
Moles = Molarity * volumeMoles = 4.78 M * 0.672 L Moles = 3.212 molesThen we calculate the new molarity of the AlCl₃ solution using that number of moles, which remains the same throughout the evaporation process:
New Molarity = 3.212 moles / 0.380 LNew Molarity = 8.45 MAnna is conducting an experiment how rather affects cell phone reception. Which of the following is the best answer
Answer:
You did not provide any details about the experiment, nor provided any answers for us from which to choose "the best answer" from. Please refine your question next time.
Explanation:
Which is one factor that scientists use to classify orders of soil?
Answer:
The scientist classify the types of soil based on the texture of the soil, the type of Rock from which they are formed and the type of organisms which live in the soil. For example red soil is formed by the weathering of reddish type of Rock which is found in that territory.
Explanation: google and me.....hope this helps
One factor which scientists used to classify orders of is Soil texture
Soil textureSoil texture is a classification strategy that scientists used to determine soil classes orders based on their physical texture.
Soil texture and soil structure are unique properties of the soil that will have a great effect on the behavior of soils, such as water holding capacity, nutrient retention and supply, drainage, and nutrient leaching.
Learn more:
https://brainly.com/question/25761065
21.4 L of gas at 42.3 °C and 681 mm Hg are heated to 221 °C, and the pressure is changed to 248 mm Hg. What is the new volume?
Answer:
V₂ = 90.42 L
Explanation:
Given data:
Initial volume = 21.4 L
Initial pressure = 681 mmHg (681/760=0.89 atm)
Initial temperature = 42.3 °C (42.3 +273 = 315.3 K)
Final temperature = 221°C (221+273 = 494 K)
Final volume = ?
Final pressure = 248 mmHg(248/760 =0.33 atm)
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
P₁V₁/T₁ = P₂V₂/T₂
V₂ = P₁V₁T₂/T₁P₂
V₂ = 0.89 atm × 21.4 L × 494 K / 315.3 K × 0.33 atm
V₂ = 9408.72 L /104.05
V₂ = 90.42 L
Heat energy always moves in which direction?
Group of answer choices
Large objects to small objects
Dark objects to light objects
Warm objects to cool objects
Smooth objects to rough objects
Answer:
large object to small objects
Answer:
The answer is C or warm objects to cool objects
Explanation:
Heat is the thermal energy flows from one substance to another when the substances differ in temperature. When you drink hot chocolate the heat from the liquid will flow to your mouth.
Which substances are componds
Answer:
Water - Formula: H2O = Hydrogen2 + Oxygen. ...
Hydrogen Peroxide - Formula: H2O2 = Hydrogen2 + Oxygen2 ...
Salt - Formula: NaCl = Sodium + Chlorine. ...
Baking Soda - Formula: NaHCO3 = Sodium + Hydrogen + Carbon + Oxygen3 .
Octane - Formula: C8H18 = Carbon8 + Hydrogen18
are 5 examples
Explanation:
When is my dad going to get the milk?
Answer:
joe.......
Explanation:
mama......
Each of the structures for CIOCI, NCOH, and CINO has atoms connected in the order given in their formulas. Identify the type of hybridization for the central atom in each compound. Write the appropriate items to their respective bins.
a. nitrogen in CINO
b. oxygen in CIOCI
c. carbon in NCOH
1. sp
2 sp2
3. sp3
Answer:
see explanation
Explanation:
If we look at the structures of each of the compounds we can be able to deduce the accurate hybridization of each of the atoms listed.
Looking at ClNO - we can see that the nitrogen atom is linked to oxygen by a double bond and linked to chlorine by a single bond retaining a lone pair on nitrogen. Hence the nitrogen is in sp2 hybridized state.
For ClOCl, the compound has a sp3 hybridized oxygen atom linked to two chlorine atoms as expected retaining two lone pairs on oxygen.
For NCOH, the carbon atom is doubly bonded to oxygen hence it is sp2 hybridized.
Answer:
A) Label 2 (Sp2)
B) Label 3 (Sp3)
C) Label 1 (Sp)
Explanation:
A) Have 7 Lone Pairs (LP) to place. 1 on N. 1 becomes a double bond. Double bonds count as 1 Electron Group. Same for single bond and LP. Add these to get 3. 3 coresponds for SP2
B) 8LP. 2LP on O. 2 bonds to O. Add to get 4. 4-> Sp3
C) 5LP. C O bond is double. single bond to N. Add to get 2-> Sp
Which structure vibrates the hammer?
stirrup
ear canal
eardrum
anvil
Answer:
Yes, the correct answer is C) Ear Canal
Explanation:
8. What energy transformations take place in a simple electric motor?
D. light --> electrical
B. kinetic --> electric
A. chemical => solar
C. electrical -> kinetic
Answer:
I don't know
Explanation:
just wanna talk because I am getting bored.
Answer:
B)
takes mechanical energy and makes it electrical
Explanation:
True or False: The polar zones on Earth are near the equator
it is for sure sure false
Answer:
False they are on the extremes of the earth they are poles they are so cold the temp is freezing there and near the equator it would hot
500.0 liters of a gas are prepared at 700 mm Hg and 200 C. The gas is placed into a tank under high pressure. What is the volume of the gas?
Answer: 143*tank temperature/tank pressure L
Explanation: too few data. Need to know the pressure and what if any, temperature change.
tank volume = (tank temp/tank pressure)*(500*200/700) = 143*tank temp/tank pressure L
At constant temperature, (500*700)/tank temp
e.g. at 1400mm Hg, 500*700/1400 = 250L
What mass of lithium phosphate (Li3PO4) is needed to prepare 500 mL (0.500 L) of a solution having a lithium ion concentration of 0.125 M?
a. 2.41 g
b. 6.75 g
c. 10.1 g
d. 19.3 g
e. 30.4 g
Answer:
a. 2.41 g
Explanation:
First we calculate the number of lithium ion moles (Li⁺) in the solution, multiplying the concentration times the volume:
500 mL ⇒ 500 / 1000 = 0.500 L
0.125 M * 0.500 L = 0.0625 mol Li⁺Then we convert moles of Li⁺ to moles of Li₃PO₄, keeping in mind that for each mole of Li₃PO₄ there are 3 Li⁺ moles:
0.0625 mol Li⁺ * [tex]\frac{1molLi_3PO_4}{3molLi^{+}}[/tex]= 0.02083 mol Li₃PO₄Finally we convert Li₃PO₄ moles to grams, using its molar mass:
0.02083 mol Li₃PO₄ * 115.79 g/mol = 2.41 gThe mass of lithium phosphate, Li₃PO₄ required to prepare the solution is 2.41 g
The correct answer to the question is Option A. 2.41 g
We'll begin by calculating the concentration of Li₃PO₄. This can be obtained as follow:
Li₃PO₄(aq) —> 3Li⁺(aq) + PO₄³¯(aq)
From the balanced equation above,
3 moles of Li⁺ is present in 1 mole of Li₃PO₄.
Therefore,
0.125 M Li⁺ will be present in = 0.125 / 3 = 0.0417 M Li₃PO₄.
Thus, the concentration of Li₃PO₄ is 0.0417 M
Next, we shall determine the number of mole of Li₃PO₄ in the solution.Molarity of Li₃PO₄ = 0.0417 M
Volume = 0.5 L
Mole of Li₃PO₄ =?Mole = Molarity x Volume
Mole of Li₃PO₄ = 0.0417 × 0.5
Mole of Li₃PO₄ = 0.02085 moleFinally, we shall determine the mass of Li₃PO₄ required to prepare the solution.Mole of Li₃PO₄ = 0.02085 mole
Molar mass of Li₃PO₄ = (3×7) + 31 + (16×4) = 116 g/mol
Mass of Li₃PO₄ =?Mass = mole × molar mass
Mass of Li₃PO₄ = 0.02085 × 116
Mass of Li₃PO₄ = 2.41 gThus, the mass of Li₃PO₄ required to prepare the solution is 2.41 g
The correct answer to the question is Option A. 2.41 g
Learn more: https://brainly.com/question/3126258
4. For the reaction A + 2B → C, the rate law is
Δ[C]/ΔT = k[A]²[B]
What are the units of the rate constant where time is measured in seconds?
a. 1/ M · s
b. 1/ M² · s
c. 1/ s
d. M²/ s
e. M/ s
The rate constant : b. 1/ M² · s
Further explanationThe reaction rate (v) shows the change in the concentration of the substance (changes in addition to concentrations for reaction products or changes in concentration reduction for reactants) per unit time.
For A + B ---> C + D
Can be formulated:
[tex]\large{\boxed{\boxed{\bold{v~=~k.[A]^a[B]^b}}}[/tex]
where
v = reaction speed, M / s
k = constant, mol¹⁻⁽ᵃ⁺ᵇ⁾. L⁽ᵃ⁺ᵇ⁾⁻¹. S⁻¹
a = reaction order to A
b = reaction order to B
[A] = [B] = concentration of substances
Units of the rate constant - k depend on rate law, so it is unique for the specific reaction
So for the rate law :
Δ[C]/ΔT = k[A]²[B] , the units are :
[tex]\tt \dfrac{M}{s}=k\times M^2\times M\\\\k=\dfrac{M/s}{M^2\times M}\\\\k=\dfrac{1}{M^2.s}[/tex]
Which is a method that can be used to separate the components of a solution?
magnetic separation
decantation
filtration
distillation
Answer:
distillation
Explanation:
i did the assignment
Answer:
distillation
Explanation:
what is the empirical formula of vitamin A ( C=83.85, H=10.56, O=5.58)
The empirical formula of vitamin A : C₂₀H₃₀O
Further explanationThe empirical formula is the smallest comparison of atoms of compound =mole ratio of the components
The principle of determining empirical formula
Determine the mass ratio of the constituent elements of the compound. Determine the mole ratio by dividing the percentage by the atomic massmol ratio of C : H : O ⇒
[tex]\tt \dfrac{83.85}{12}\div \dfrac{10.56}{1}\div \dfrac{5.58}{16}\\\\6.9875\div 10.56\div 0.34875\rightarrow divide~by~smallest(0.34875)\\\\20\div 30\div 1[/tex]
whats the reason you can float a paperclip on water?
Answer:
because it is not a rock and it is not thick so it can float
Explanation:
because it is thin and light