Answer:
10%-saline solution = 60mL
15%-saline solution = 40mL
Explanation:
Let
10%-saline solution = x
15%-saline solution = y
x + y = 100
0.1x + 0.15y = 100*0.12
x + y = 100 (1)
0.1x + 0.15y = 12 (2)
from (1)
x = 100 - y
Substitute x = 100 - y into
0.1x + 0.15y = 12
0.1(100 - y) + 0.15y = 12
10 - 0.1y + 0.15y = 12
- 0.1y + 0.15y = 12 - 10
0.05y = 2
y = 2 / 0.05
y = 40mL
Substitute y = 40 into
x + y = 100
x + 40 = 100
x = 100 - 40
x = 60mL
10%-saline solution = 60mL
15%-saline solution = 40mL
if a car travels 350 miles in 7 hours what was the speed
Answer:
50 mph
Explanation:
Answer:
5 miles per hour
Explanation:
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PLEASE HELP
Electrical devices have been designed to convert electrical energy to other useful
forms of energy. Choose the device which converts electrical energy to kinetic
energy.
Answer:
B. Fan
Explanation:
The device in the options which converts electrical energy to kinetic
energy is the Fan.
When the fan is plugged to a an electric power source, the electrical energy gets converted to kinetic energy as a result of the movement of the blades in which Kinetic energy is defined as the energy as a result of the motion of a particle or substance.
How many rings/energy levels would the Bohe model for an element
have if it had 12 electrons?
PLEASE HELP
what is love made out of ?
An object is moving across a surface, but it does not gain or lose speed. Which best describes the object’s force?
Answer:
Explanation:
the vector sum of all such forces which equals zero for an object at rest. CASE 1: Considering a basketball of weight 1kg, if it has been kept stationary on the ground, there are two forces acting on it. These are it's weight (gravity) and equal and opposite force from the ground (normal reaction).
Answer:
The net force is zero. :)
Explanation:
Which of the following chemical formulas contains the most molecules?
A. 5CO
B. 3H2O
C. 2Fe2O3
D. 4C3H8
HELPP ASAP
What do the colors on the periodic table show?
A. which element it is
B. the metallic properties of the element
C. the types of compounds the element can make
D. whether the element is a solid, a liquid, or a gas at room temperature
Answer:
Periodic tables can use color to identify other element characteristics. For example, an electronegativity periodic table color codes the elements based on how electronegative they are. The valence periodic table uses color to identify the most common valence state for each element.Oct 2, 2019
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The color given to a the elements in periodic table is to characteristics of the elements mainly to identify whether they are solid, gas or liquid. Thus option D is correct.
What is periodic table?A periodic table contains all the discovered elements which are classified into different groups and periods. Groups are vertical columns of elements with similar properties and same number of valence electrons.
Periods are horizontal rows from left to right with an increase in atomic number. There are 18 groups and 7 periods in periodic table. Each group has given each color and some elements showing exceptional characteristics such as hydrogen and helium have separate colors.
All the first group elements called alkali metals have one color and the second groups elements with another color, All the d-block elements are given the same colour and metals in p-block elements have the same color.
Similarly, all the metalloids have one color and all other gases have the same colour in which inert gas group and halogen group have seperate colours.
Hence, the color in periodic table helps to identify the element's nature like its state also. Thus option D is correct.
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Which elements are abundant in visible universe
Hydrogen is the most abundant element in the Universe; helium is second. However, after this, the rank of abundance does not continue to correspond to the atomic number; oxygen has abundance rank 3, but atomic number 8. All others are substantially less common.
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how do humans benefit from photosynthesis
Answer:
Explanation:
Without photosynthesis there would be no oxygen in the earth's atmosphere and we wouldn't be here!
C3H5OH + 3 O2 --> CO2 + H2O When balancing the equation above, how many molecules of CO2 and H2O are produced? The first half is already balanced.
Answer:
1.8069*10²⁴molecules of CO₂ and H₂O are produced.
Explanation:
C₃H₅OH + O₂ → CO₂ + H₂O
The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.
Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts
Left side: 3 C, 6 H and 3 O.
Right side: 1 C, 2 H and 3 O.
The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.
By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.
So, balancing the C:
C₃H₅OH + O₂ → 3 CO₂ + H₂O
Then:
Left side: 3 C, 6 H and 3 O.
Right side: 3 C, 2 H and 7 O.
Now, balancing the H:
C₃H₅OH + O₂ → 3 CO₂ + 3 H₂O
Then:
Left side: 3 C, 6 H and 3 O.
Right side: 3 C, 6 H and 9 O.
Finally, balancing the O:
C₃H₅OH + 4 O₂ → 3 CO₂ + 3 H₂O
Then:
Left side: 3 C, 6 H and 9 O.
Right side: 3 C, 6 H and 9 O.
Since you have the same amount of each element on each side of the reaction, the reaction is balanced. Then 3 moles of CO₂ and 3 moles of H₂O are produced.
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole and it applies to any substance.
Then the following rule of three applies: if 1 mole contains 6.023*10²³ molecules, then 3 moles of CO₂ or 3 moles of H₂O, how many molecules does it contain?
[tex]amount of molecules=\frac{3 moles* 6.023*10^{23} molecules}{1 mole}[/tex]
amount of molecules= 1.8069*10²⁴
1.8069*10²⁴ molecules of CO₂ and H₂O are produced.
Reaction type
Li + N2
Li3N
Answer:
Combination or synthesis
Explanation:
The given reaction is:
6Li + N₂ → 2 Li₃N
This reaction is a synthesis or combination reaction. 6 moles of Li combines with nitrogen gas to produce 2 moles of Li₃N.
In a synthesis reaction, two substances combines together to give singular product. The formation of compounds from the union of the constituent elements falls into this category of reaction.How much radium-226 will remain from a 20 gram sample after 4800 years?
Answer:
2.5 g mass of Ra-226 will remain after 4800 years.
Explanation:
Given data:
Mass of Ra-226 = 20 g
Sample remain after 4800 years = ?
Solution:
Half life of Ra-226 = 1600 years
Number of half lives passed = T elapsed / half life
Number of half lives passed = 4800 year / 1600 year
Number of half lives passed = 3
At time zero = 20 g
At first half life = 20 g/2 = 10 g
At 2nd half life = 10 g/2 = 5 g
At 3rd half life = 5 g/2 = 2.5 g
Thus, 2.5 g mass of Ra-226 will remain after 4800 years.
ill attach a picture
Answer:
35.50
Explanation:
There are two stable isotopes, 35Cl (75.77%) and 37Cl (24.23%), giving chlorine a standard atomic weight of 35.45
7. Base your answer to the following question on the information below and on your knowledge of biology A student designed an experiment to investigate a claim that athletes would have lower heart rates than nonathletes during exercise. After the students classified themselves as an athlete or a nonathlete, their resting pulses were determined. Then all the students performed the same exercise for four minutes and their heart rates were determined by recording the pulse rate in beats per minute. The students continued to measure their pulse rates for an additional four minutes. The average heart rate per minute for each group was determined. The data were recorded, as shown on the table below Average Heart Rate Response to Exercise (beats per minute) Time (minutes) Athlete Students Nonathlete Students Resting Pulse 68 72 1 76 78 2 82 90 Exercising Period 3 115 95 110 4 130 5 100 125 6 95 120 After Exercise 7 85 100 8 68 95 2.4 To improve the validity of the conclusion reached in this experiment, the students should repeat the experiment A) disregarding any data that don't fit the hypothesis B) with a larger number of athletes and nonathletes C) comparing the heart rates and breathing rates of males and females D) with the athletes doing different exercises than the nonathletes
Please Help!
Which change takes place at the freezing point of a substance?
Group of answer choices
A. A gas becomes a liquid
B. A solid becomes a gas
C. A liquid become a solid
D. A gas becomes a solid
please also give me an explanation since I do not understand this.
Answer:
❤C. A liquad becomes a solid❤
Explanation:
✌When you freeze water its a scientific fact that it becomes solid.✌
Part of an important cellular process involving a DNA strand is modeled below
12000
What is the purpose of this cellular process?
F Preserving genetic information for future generations
G Deleting the information in the sequence produced from the DNA template
# Transcribing information in the DNA sequence for use by the cell
J Producing more nucleotides for the DNA sequence
Answer: transcribing information to the dna sequence for use by the cell
Explanation:
The oxidation # (charge) of an element called "lindenium "Ld is + 1 and the oxidation # (charge) of an element called "mendezine symbol "Mz, is -2. What is the chemical formula for the compound called lindenium mendezide?
Answer:
Ld₂Mz
General Formulas and Concepts:
Chemistry - Compounds
Valence shellsWriting chemical compoundsBalancing chargesExplanation:
Step 1: Define
"Lindenium" Ld w/ oxidation charge of +1
"Mendezine" Mz w/ oxidation charge of -2
Step 2: Write Compound
To balance out the charges to be neutral (0), we must counter balance the amount of Ld's with Mz's. We need 2 Ld's with 1 Mz to create a compound with a neutral charge:
2Ld¹⁺ + Mz²⁻
2(+1) + (-2) = (+2) + (-2) = 0 (neutral charge)
Therefore, our compound must be Ld₂Mz.
What is the difference between chlorine -35 and chlorine -37?
Answer:
Free chlorine involves the amount of chlorine that's able to sanitize contaminants, while combined chlorine refers to chlorine that has combined directly with the contaminants. Total chlorine is basically the sum of free chlorine and combined chlorine.
Explanation:
chlorine -35 being chlorine
chlorine -37 being free chlorine
d. what happens when an iron nail is kept in copper sulphate solution?
Answer:
it changes color from blue to light green.
Explanation:
due to copper iron nail functions
Answer:
give the other person brainlieset plz
Explanation:
What do the elements in group 18 have in common?
Answer: They are all odorless, colorless, monatomic gases with very low chemical reactivity.
Explanation: Plz give brainliest
What is the mass of 2.25 mol of the element Iron (Fe)?
Choose the correct set up from the given choices.
a. You would divided 2.25 mol by (55.84 mol divided by 1 gram)
b. You would multiply 2.25 mol by (1mol divided by 55.84 g)
c. You would multiply 2.25 mol by (55.84g divided by 1 mol)
d. You would divide 2.25 mol by (1 mol divided by 55.84g)
Mole measure the number of elementary entities of a given substance that are present in a given sample. To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol). Therefore option c is correct option.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance.
Mathematically,
Mole of Fe element= mass of Fe element÷ Molar mass of Fe element
mass= Mole of Fe element ×Molar mass of Fe element
Substituting the given values in above formula we get
mass= 2.25 mol× 55.84 g/mole
mass= 2.25 mol× 55.84 g/mole
To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol).
Therefore option c is correct option.
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what makes one of your cells you ?
equivalent mass of AL2O3
Answer:
[tex]Mass = 102g[/tex]
Explanation:
Given
Compound: [tex]Al_2O_3[/tex]
Required
Determine the equivalent mass
In the above compound, we have: 2 Al and 3 (O)
The atomic mass of Aluminium is:
[tex]Al = 27[/tex]
The atomic mass of Oxygen is:
[tex](O) = 16[/tex]
So, the equivalent mass is:
[tex]Mass = 2 * 27 + 3 * 16[/tex]
[tex]Mass = 54 + 48[/tex]
[tex]Mass = 102g[/tex]
What did you include in your response? Check all that
apply.
O No, thermal energy is not being transferred by
radiation in this image.
O The eggs are in direct contact with the metal pan,
which is in direct contact with the gas flame.
O Thermal energy is being transferred by conduction.
O Radiation transfers thermal energy by
electromagnetic waves.
O Radiation does not transfer thermal energy by
direct contact.
Which of the following scenarios would not prompt the cell to start dividing
Answer:
what r the options??????
What is the mass of a lead block that has a volume of 30 mL?
O 3.39 grams
O .377 mL
O 265 mL
O 339 grams
Answer:
d
Explanation:
i think it's d, but I'm not sure. my answer is a little different but maybe i used a different number for the density of lead (11.35g/cc)
Mercury is an element that forms during _____
Answer:
forms of mercury
Explanation:
Answer:
Explanation:
Mercury is an element and a metal that is found in air, water, and soil.Mercury rarely occurs uncombined in nature, but can be found as droplets in cinnabar (mercury sulfide) ores. China and Kyrgyzstan are the main producers of mercury. The metal is obtained by heating cinnabar in a current of air and condensing the vapour.
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A scientist thinks he found a new metal, so he published a paper about this metal. About 1 week after the scientist published the paper, you noticed a problem with the paper the scientist wrote. You noticed that this metal was not a new metal. In fact, this metal was discovered years ago. You determined this when you saw the atomic emission spectrum. As you read the article, you remembered that each atomic emission spectrum is unique to each element and the atomic emission spectrum matched one that was already discovered. Using the techniques from Chemistry, you ran a Flame Test with a piece of the metal (the metal is safe to use) that you had shipped to you. You found the metal turned the flame yellow. What metal did you have in your possession?
**ANSWER CHOICES**
*Barium
*Calcium
*Strontium
*Copper
*Sodium
Answer:
Sodium
because it burns with a yellow-orange flame.
Explanation:
It relates with Barium which burns with yellowish green flame
why sodium and chlorine are active element
help meeeeeeeeeeeee its impossibleeeeee
Answer:
Nice! If only....
Explanation:
Answer:
omg lol what even is this