Answer:
Two
Explanation:
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]
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
why sodium and chlorine are active element
Plants give off oxygen as part of photosynthesis. Explain the impact of this process on humans?
Answer:
i think it haven't impact because oxygen is very sensitive for our life and from plants there is so many kinds of food sources soo
A layer of sandstone is found on top of a layer of shale
Answer: Yes it is
Explanation:
How many moles in 435 liters of Krypton gas at STP?
19.4 mol Kr
General Formulas and Concepts:Chemistry
Stoichiometry
Using Dimensional AnalysisGas Laws
STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 KMath
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right Explanation:Step 1: Define
435 L Kr at STP
Step 2: Identify Conversions
[STP] 22.4 L = 1 mol
Step 3: Convert
[tex]435 \ L \ Kr(\frac{1 \ mol \ Kr}{22.4 \ L \ Kr} )[/tex] = 19.4196 mol Kr
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
19.4196 mol Kr ≈ 19.4 mol Kr
How would you define what the conductivity of a substance is?
Answer:
Conductivity of a substance is defined as 'the ability or power to conduct or transmit heat, electricity, or sound'.
Explanation:
hope it helps
plzz mark as brainliest....
The percentage by volume of oxygen in clean and dry air is approximately
Answer:
[tex]\huge\bf\underline{\underline{\pink{A}\orange{N}\red{S}\green{W}\purple{E}\blue{R}}}[/tex]
ONLY 20.95% IN THE AIR
:)
▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃
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
What group is not assigned electron affinities on the periodic table?
Answer:
Explanation:
halogen group
Electron affinities are negative numbers because energy is released. The elements of the halogen group (Group 17) gain electrons most readily, as can be seen from their large negative electron affinitie
Answer:
tbh i liked how u ghosted me
Explanation:
uses of indicators in points?
Answer:
The common application of indicators is the detection of end points of titrations. The colour of an indicator alters when the acidity or the oxidizing strength of the solution, or the concentration of a certain chemical species, reaches a critical range of values.
Jase mixed 2 liquids together and to his amazement, he saw that a solid had formed! What is this solid known as?
(will give brainliest)
Answer:
......
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
How long does it take for 87.5 % of each isotope(Krypton-73, Krypton-74, Krypton-76, and Krypton-81) to decay?
How many rings/energy levels would the Bohe model for an element
have if it had 12 electrons?
PLEASE HELP
Typhoons are large storms that form over the Pacific Ocean Hurricanes are large storms that form over the Atlantic Ocean. Which of the following are essential components in the formation of a hurricane
or a lyphoon
A High pressure, high temperature, cyclonic winds, dry air
B. High pressure cool temperature, strong winds, humid air
cWarm front, clouds, low pressure, high slevation
D Low pressure, warm temperature, warm ocean waters, spiraling winds
Formula for the compound that contains Mg2+ and O2-
Answer:
MgO.
Explanation:
charges of both satisfy one another (balanced) -- producing a compound MgO.
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.
The central atom in PbSO4 is..............???????
Answer:
The central atom is S.
Explanation:
Look at the structure.
Please help me !!!!
Answer:
1) clouds 2) quick 3) near 4) levels 5)nucleus 6) two 7) eight 8) eighteen 9) pairs 10) properties
Explanation:
hope i helped!
Answer:
1. clouds
2. quick
3. near
4. levels
5. nucleus
6. two
7. eight
8. eighteen
9. pairs
10. properties
I do not know if I got 6-8 correctly but I got the other answersWhich of the following best describes spectator ions? A. that do not participate in the reaction B. lons made when compounds dissolve in water C. that are made of a single element D. Ions that combine to form a precipitate
Answer: A. that do not participate in the reaction
Answer:
a
Explanation:
a p e x :)
what hypothesis is best for chemical reaction?
will give Brainliest
Answer:
If the reactants in the chemical reactions are known, then the products can be predicted because the pattern of the chemical reactions is being followed. The pattern for a single replacement is A + BC --> AC + B. This is like the Hear It Pop Chemical Reaction which is also an example of the single replacement.
Explanation:
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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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
When force are ____ the object does not move
when forces are balanced the object does not move.
Explanation:
if you and your friend push both sides of the chair at the same time with the same amount of strength the chair wouldn't move.
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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The transfer of energy in the form of invisible waves is
Answer:
Radiation
Explanation:
how different are the duck leeches offsprings from their parents
About ______ impact the creators have been recognized on earth.
A) one thousand
B) 50
C)500
D)150
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.