Answer:
Concave Lenses Are for the Nearsighted, Convex for the Farsighted. Concave lenses are used in eyeglasses that correct nearsightedness.
Explanation:
The total age of 5 children aged 3 years is 50 years. Find the age of the youngest and oldest child?
Answer: See explanation
Explanation:
Here's the correct question:
The total ages of 5 children born at the intervals of 3 years each is 50 years. Find the age of the youngest and the oldest child.
From the information given, we can then make the following assumption with regards to their ages.
First child = y
Second child = y + 3.
Third child = y + 6
Fourth child = y + 9
Fifth child = y + 12
Therefore, y + y+3 + y+6 + y+9 + y+12 = 50
5y + 30 = 50
5y = 50 - 30
5y = 20
y = 20/5
y = 4
Youngest child = 4 years
Oldest child = y + 12 = 4 + 12 = 16 years
The elements listed in the periodic table account
for only this percentage of the matter in
the universe.
Answer:
Only 4 %
Explanation:
Just about 4 percent of the known universe overall mass consists of atomic nuclei and is therefore described by chemical components. This proportion is around 15 percent of the total mass, with dark energy becoming the majority of the material .
What important function do currents and areas of upwelling provide for living things
in the sea?
Recycles the ocean water through evaporation and precipitation
Brings nutrients up from deeper water for use by organisms
Mixes land and sea organisms to broaden the food web
Allows Earth to have weather and climate changes
What is the mass of 5 liters of fluorine (F2) gas at STP?
Answer:
The molar density of any ideal gas at STP is:
1 mol / 22.4 L = 0.04464 mol / L
The molar mass of F2 is: 2(19) = 38 g/mol
0.04464 mol / L * (38 g / mol) = 1.70 g/L
Explanation:
Draw the structure of the peptide DTLH, showing the backbone and side-chain atoms, at its isoelectric point. Draw the molecule on the canvas by choosing buttons from the Tools (for bonds and charges), Atoms, and Templates toolbars. Draw peptide molecule as zwitter ion.
Answer:
Explanation:
A peptide is any class of organic compounds composed of different numbers of amino acids in which the amine of one is reacted with the carboxylic acid of the next to form an amine bond. The peptide of DTLH is composed of the following amino acids:
Asp-Thr-Leu-His
Their structures are first drawn out in the image attached below. This is followed by the isoelectric structure of the peptide DTLH
A standard 10.00 g mass is weighed on an analytical balance 100 times. The average and standard deviation obtained gives 10.12 ± 0.03 g. A calibration service is called. After the balance is recalibrated, the new measurements show 10.00 ± 0.03 g. Did the recalibration result in improved accuracy or precision?
Answer:
There was an improvement in accuracy. There was no change in precision.
Explanation:
The average mass after recalibration is closer to the mass of the standard, so the recalibration improved the accuracy (the measurement is closer to an accepted 'true' value).
The standard deviation did not change, so the precision (or how disperse the measurements are) was not affected.
Help pls!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
water/d
Explanation:
Which process directly moves nutrients from plants to the air
A) Percolation
B) Transportation
C) Assimilation
D) Photosynthesis
Answer:
Plants release oxygen in the process of Photosynthesis
Explanation:
Deforestation happens when people try to provide more:
a) water
b) waste
c) timber
d) oxygen.
Which of the following observations about burning sugar provides evidence of a
chemical reaction?
a. Heat is added to the sugar crystals.
b. The sugar melts and becomes a liquid.
с
C. The temperature of the sugar increases.
d. Gas is produced as the sugar turns black.
1 Pt
А
B
D
In the picture below, ammonia and bleach are mixed together. How many nitrogen (N) atoms will be in the products?
1
ammonia: NH3 (one nitrogen)
bleach: NaOCl (zero nitrogen)
If an oxygen molecule is moving at 4.78 x 104
cm.s-, what is its speed in mi hrl?
Show work please
Answer: 1075.5 mph
Explanation:anything moving at 4.78*10^4 cm/sec
equivalent to
cm —> miles = 1/1.6*10^5
sec —> hr = 1/3600
[4.78*10^4]*3600/1.6*10^5 = 1075.5 mph
what happens when hydrogen gas is passed over hot ferric oxide
Answer:
When hydrogen is passed over hot ferric oxide (FeO) hydrogen reacts with oxygen present in the compound and forms water (H2O) and pure Iron
Explanation:
Answer:When hydrogen gas is passed over hot copper oxide, the black coating on the surface turns brown as the reverse reaction takes place and copper is obtained.
Explanation:
What is a common effect of warm ocean currents on nearby coastlines?
A. Low wind speeds
B. Lower temperatures
C. Changing wind directions
D. Increased clouds and precipitation
What is the mass in grams of 0.7350 moles of sodium?
Answer:
Explanation:
1 mol of sodium = 23 grams (use the number on your periodic table).
0.7350 mol sodium = x
Cross multiply
1*x = 0.7350 * 23
x = 16.905
You will get slightly less than this, depending on your periodic table. But the method will be the same.
In chemical reactions, a product is
Select one:
any substance that is made from the least number of atoms
any substance to the right of the arrow
any substance that is made of the greatest number of atoms
ubstance that s to the left of the arrow
The picture has my question
Answer:
b or c
Explanation:
A species is
O the least specific group
O not a group at all
o the most specific group
the largest group
__Fe + ___ Cl2 --> ___FeCl3
The coefficient on iron for this equation is:
A 4
B 2
C 1
D 3
When Lithium chloride is dissolved in water, there is a steep rise in the temperature of the water. Based on the evidence, is the dissolution of lithium chloride endothermic, exothermic, or neither? Explain.
Answer:
When some LiCl is dissolved in water, the temperature of the water increases. This means that: (A) the strength of the intermolecular forces between the water molecules is stronger than the bond energy within the LiCl lattice.
Explanation:
When Lithium chloride is dissolved in water, there is a steep rise in the temperature of the water. Based on this evidence, the dissolution of lithium chloride is exothermic.
What is an Exothermic reaction?An exothermic reaction may be defined as a type of reaction in which energy is liberated as a product in the form of light or heat. For these types of reactions, the overall standard enthalpy change ΔH⚬ is negative. It is one of the thermodynamic processes other than endothermic.
In the reaction, lithium intensely reacts with water in order to form lithium hydroxide and highly flammable hydrogen which liberated energy and leads to the steep rise in the temperature of the product compounds. This enhancement in the temperature is accurate evidence of an exothermic reaction.
Therefore, on the basis of the evidence that the reaction of lithium chloride in water causes a steep rise in the temperature of the water represents an exothermic reaction.
To learn more about Exothermic reaction, refer to the link:
https://brainly.com/question/2924714
#SPJ6
[24 points] A sample of soil has a total volume of 205 cm3. The soil mass when saturated is 361 g. A specific yield test was conducted on the soil by allowing the sample to drain for 24 hours. After drainage the sample mass was 295 g. The soil was then dried and weighed 284 g. What are the specific yield [8 points], specific retention [8 points], and porosity [8 points] of the sample
Answer:
Follows are the solution to the given question:
Explanation:
Dry Soil weight = solid soil weight = [tex]284 \ grams[/tex]
solid soil volume =[tex]205 \ cc[/tex]
saturated mass soil = [tex]361 \ g[/tex]
The weight of the soil after drainage is =[tex]295 \ g[/tex]
Water weight for soil saturation = [tex](361-284) = 77 \ g[/tex]
Water volume required for soil saturation =[tex]\frac{77}{1} = 77 \ cc[/tex]
Sample volume of water: [tex]= \frac{\text{water density}}{\text{water density input}}[/tex]
[tex]= 361- 295 \\\\ = 66 \ cc[/tex]
Soil water retained volume = (draining field weight - dry soil weight)
[tex]= 295 - 284 \\\\ = 11 \ cc.[/tex]
[tex]\text{POROSITY}= \frac{\text{Vehicle volume}}{\text{total volume Soil}}[/tex]
[tex]= \frac{77}{(205 + 77)} \\\\= \frac{77}{(282)} \\\\ = 27.30 \%[/tex]
(Its saturated water volume is equal to the volume of voids)
[tex]\text{YIELD SPECIFIC} = \frac{\text{Soil water volume}}{\text{Soil volume total}}[/tex]
[tex]= \frac{66}{(205+77)}\\\\= \frac{66}{(282)}\\\\=0.2340\\\\ = 0.23[/tex]
[tex]\text{Specific Retention}= \frac{\text{Volume of soil water}}{\text{Total soil volume}}[/tex]
[tex]= \frac{11}{282} \\\\= 0.0390 \\\\ = 0.04[/tex]
How many moles of nitrogen are in 100.0 grams of barium nitrate?
Answer:
Hope this help you
Explanation:
The answer is 261.3368. We assume you are converting between grams Barium Nitrate and mole. You can view more details on each measurement unit: molecular weight of Barium Nitrate or mol The molecular formula for Barium Nitrate is Ba(NO3)2.
Answer:
0.382
Explanation:
For the reaction between zinc metal and hydrochloric acid (aqueous) producing zinc chloride (aqueous) and hydrogen gas
write a balanced equation for this reaction
classify the reaction
Answer: Zn + 2HCl —> ZnCl2 + H2 redox
Explanation:
H+ reduced to H
Zn oxidised to Zn++
During a chemistry lab exercise, a student isolates a compound at STP. In her
lab report, she has identified it as an ionic compound. If it is an ionic compound, it
will likely have a _________boiling point and be a _______ at STP.
Choose the answer with the words in the correct order that complete the
passage.
A. high; liquid
B. low; gas
C. high; solid
D. low; solid
please answer asap thank you !! :)
Ionic compounds have a high boiling point and be a solid at STP.
What is ionic compound?Ionic compounds are those compounds which are formed due to high electrostatic attraction between cations and anions.
Ionic compounds are generally present in the solid state because of the presence of strong ionic bond. And due to this rigid structure boiling point of ionic compounds are very high as they want more energy to break their bonds.
Therefor, at standard temperature pressure (STP) ionic compounds will likely have a high boiling point and be a solid at STP.
To learn more about ionic compounds, visit below link:
https://brainly.com/question/11638999
Help !!A student examines a picture of an important biological molecule in a textbook and writes four statements about the molecule in a chart
1. The molecule is found in the nucleus,
2. The molecule is made up of chromosomes.
3. The molecule carries genetic information.
4. The molecule contains genes.
Which statement needs to be revised to make it true? statement 1 statement 2 statement 3 statement 4
Answer:
Statement 2 (The molecule is made up of chromosomes)
Explanation:
This question is describing DNA, as the biological molecule. DNA is a type of nucleic acid that functions in the storage of genetic information in the cell. This means that contained in the DNA, are segments that code for proteins called GENES. It is contained in the nucleus of eukaryotic cells where it is wrapped around structures called CHROMOSOMES.
BASED on the four statements given by the student, which happens to be characteristics of this molecule, the statement 2, which states that the molecule is made up of chromosomes needs to be revised to make it true. This is because DNA is not made up of chromosomes but rather DNA is contained in chromosomes.
A mixture of cyclopropane (C3H6) and oxygen (O2) is sometimes used as a general anesthetic. In a mixture, the partial pressures of cyclopropane and oxygen are 170. torr and 570. torr, respectively. Calculate the ratio of the moles of oxygen to the moles of cyclopropane in the mixture.
Answer:
0.30
Explanation:
Provided that the volume and pressure remains constant
[(Pressure of cyclopropane)/ (Pressure of Oxygen)] = [(no. Of moles of cyclopropane)/(no. Of moles of Oxygen)]
Pressure of cyclopropane= 170. torr
Pressure of Oxygen= 570. torr
If we substitute the values
[(no. Of moles of cyclopropane)/(no. Of moles of Oxygen)] = 170/570
[(no. Of moles of cyclopropane)/(no. Of moles of Oxygen)] = 0.30
Hence, the ratio of the moles of oxygen to the moles of cyclopropane in the mixture is 0.30
Atmospheric pressure decreases as altitude increases. In other words, there is more air pushing down on you at sea level, and there is less air pressure pushing down on you when you are on a mountain.
If hexane (C6H14C6H14), octane (C8H18C8H18), and octanol (C8H17OHC8H17OH) are heated evenly at different altitudes, rank them according to the order in which you would expect them to begin boiling.
A) Hexane at high altitude.B) Octane at high altitude.C) Octane at sea level.D) Octanol at sea level.
Answer:
Octanol at sea level> Octane at sea level > Octane at high altitude > Hexane at high altitude
Explanation:
Let us have it behind our minds that the boiling points of alkanes depends on the length of the alkyl chain. The longer the chain length, the higher the boiling point of the alkane.
Also, octanol has hydrogen bonding between its molecules in addition to dispersion forces, hence it has a higher boiling point than octane and hexane at sea level.
So, the order of boiling points required at the specified altitudes is;
Octanol at sea level> Octane at sea level > Octane at high altitude > Hexane at high altitude
How many liters of N2 gas are in 2.4 moles at STP?
Answer:
any gas takes up 22.4L per mole so 2.4*22.4=53.76
Explanation:
In 2.4 moles at STP, 53.79 litres of N2 gas are present.
What are moles?Moles are defined as the amount of substance of a system that contain the same number of entities as the number of atoms in 12g of carbon 12.
What is STP?STP is defined as the standard temperature and pressure. At STP, as system has s temperature of zero degree centigrade or 273 Kelvin and the pressure is 1 atm.
PV= nRT
P= 1 atm
V= ?
n= 2.4 moles
R= 0.0821 L atm /K/mol
1 x V = 2.4 x 0.0821 x 273
V = 53.79 litres
Hence, 53.79 litres of N2 gas is present in 2.4 moles at STP.
To learn more about moles and STP here
https://brainly.com/question/9945437
#SPJ2
The orbit closest to the nucleus has ___________ energy.
Answer:
inonic bonds with cavalent bonds
Explanation:
ionic bonds
Please help!!! It's Due TODAY!!! Imagine a made up polyatomic ion called tritoborate. Calcium tritoborate has the formula Ca2B3O8.
a. What is the formula for tritoborate? You must include the charge (both the sign and the
magnitude). (2 pts)
b. Write both the formula and the name for the compound formed when Fe3+ combines
with tritoborate? (2 pts)
Answer:
a. The formula for tritoborate ion is B₃O₈²⁻
b. The formula of the compound formed will be Fe₂(B₃O₈)₃ and the name will be Iron (iii) tritoborate
Explanation:
The formation of compounds by atoms of elements occurs in accordance with the valencies of the elements. Valency refers to the combining power of an element. For metallic elements, it is usually the number of electrons they can give up or lose while for non-metallic elements, it is the number of electrons they can accept. The valency of an atom of an element is related to its oxidation number. Metals have positive oxidation numbers while non-metals have negative oxidation numbers. Sometimes, two or more atoms combine together and react as a single unit and may carry a positive or negative charge. These are known as a radicals. For example, ammonium ion, NH₄⁺.
In the given question, calcium tritoborate, CaB₃O₈ is formed from the combination of calcium ion and tritoborate ion. Calcium ion carries the charge of +2, therefore, the tritoborate ion must have a charge of -2 in order to form a compound since the overal charge on a compound is zero.
a. let the tritoborate ion be represented by X
Ca = +2, X = ?
+2 + X = 0
X = -2
Thus, the formula for tritoborate ion is B₃O₈²⁻
b. When tritoborate ion combines with iron (iii) ion, Fe³⁺, two moles of Fe³⁺ will be required to react with three moles of B₃O₈²⁻ in order to have a neutral compound. The formula of the compound formed will be: Fe₂(B₃O₈)₃ and the name will be Iron (iii) tritoborate