Answer:
Average atomic mass = 10.8 amu
Explanation:
Given data:
Average atomic mass = ?
Percentage of boron having mass 10.0129371 amu = 19.9%
Percentage of boron having mass 11.0093055 amu = 80.1%
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (19.9×10.0129371 )+(80.1×11.0093055) /100
Average atomic mass = 199.3 + 881.8 / 100
Average atomic mass = 1081.1 / 100
Average atomic mass = 10.8 amu.
__________________ to represent dominant alleles and used __________________ ___________________ to represent recessive alleles.
Answer:
Explanation:
Mendel used letters to represent dominant and recessive factors. Likewise, geneticists now use letters to represent alleles. Capital letters refer to dominant alleles, and lowercase letters refer to recessive alleles.
Someone help Match them
List 3 countries known to have poor water quality.
Answer
Ethiopia, Niger, Chad
Exlination-
When a wavelength (increases/decreases) the frequency (increases/decreases) and the energy (increases/decreases)
Answer:
As a wavelength increases in size, its frequency and energy (E) decrease. From these equations you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer. There are two basic types of waves: mechanical and electromagnetic
Explanation:
hope it helps
plz mark it as brainlist
Chemical Equations and Reactions WS
Answer:
1,1,1
decomposition reaction
Explanation:
The reaction equation is given as:
_Ca(OH)₂ → _CaO + _H₂O
This reaction is a decomposition reaction in which a single reactant breaks down to give two or more products.
To balance the equation, we assign variables a, b and c, then we use a mathematical approach to solve the problem;
aCa(OH)₂ → bCaO + cH₂O
Conserving Ca : a = b
O: 2a = b + c
H: 2a = 2c
let a = 1, b = 1 , c = 1
Identify the type of the following chemical reaction.
Answer:
Hydrolysis reaction
Explanation:
137g of Ba + ______ g oh I --> 391g of BaI2
Answer:
Explanation:
Is it worth it? Joy
How many moles are in 20g of potassium (K)?
Explanation:
Hi for this one u just need to remember and use the equation.
[tex]moles = \frac{mass}{mr} [/tex]
then u find mr of potassium which is 39.1.
then u do
[tex] \frac{20}{39.1} [/tex]
you get the answer as 0.5115 write ur answer to 3 significant figures which will be 0.512 moles .
hope this helps :)
Write a question you have about water
Answer:
How many gallons of water are on earth?
Why does salt water make you sticky and burn our eyes so bad?
Explanation:
These are just a couple questions I came up with just now
I hope that this helps
1. How many moles of magnesium is 3.01 x 10^23 atoms of magnesium?
Answer:
0.5 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{3.01 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{3.01}{6.02} = 0.5 \\ [/tex]
We have the final answer as
0.5 molesHope this helps you
Does the motion of the moon affects how we see it from Earth? *
Alexandra is researching the effects of plate tectonics have on the shape of the earth. Which of the following is a result of plate tectonics
a. The species of grass on an island
b. Formation of mountains on land
c. Earths core temperature
d. The amount of precipitation over oceans
(Science)
Answer:
b
Explanation:
the plates crash into each other and form a mountain yea that's it
HELP PLEASEEE!!! THANK YOUU
Answer:
D: Condensation
Explanation:
Hope This Helps! :)
Convert the following number from scientific notation to standard notation:
7.80 x 105
Answer:
Call of balls massive sack
Explanation:
Yoooo
Why do all measurements have a degree of uncertainty?
Answer:
All measurements have a degree of uncertaintyregardless of precision and accuracy. This is caused by two factors, the limitation of the measuring instrument (systematic error) and the skill of the experimenter making the measurements (random error).
What could you say about the melting point of CO2?
O None of these answers are correct
O I'm not sure CO2 isn't an ionic compound.
O CO2 doesn't melt
O high melting point
Answer:
None of these answers are correct.
CO2 is a covalent not ionic compound
It DOES melt, though at a very low temperature
Its melting point is negative, not high
Explanation:
An atom of an unknown element contains 17 protons and 19 neutrons. The total number of electrons present in a neutral atom of this element is
Answer:
This isotope of fluorine has 9 protons, 9 electrons and 10 neutrons.
Explanation:
The atomic number is the number of protons ( p + ) . In a neutral atom, the number of electrons ( e − ) equals the number of protons. Mass number is the sum of the protons and neutrons ( n 0 ) of a particular isotope. If you have mass number and atomic number, subtract the atomic number from the mass number to get the number of neutrons. ( Mass number ) − ( atomic number ) = number of neutrons .
There are:
9 protons
9 electrons
10 neutrons
Fluorine is the element in question, as its atomic number is 9 . You would name this particular isotope using the mass number. It would be called fluorine-19.
The nuclear or isotopic notation would be 19 9 F
When there are 0.0814 moles of hockey pucks how many hockey pucks are there?
Answer:
4.9 x 10²²hockey pucks
Explanation:
Given parameters:
Number of moles of hockey = 0.0814moles
Unknown:
Number of pucks there = ?
Solution:
A mole of a substance is made up of Avogadro's number of particles.
Therefore;
1 mole of hockey pucks will contain 6.02 x 10²³ hockey pucks
0.0814 mole of hockey pucks will contain :
0.0814 x 6.02 x 10²³ = 4.9 x 10²²hockey pucks
How many moles of nitrogen gas will occupy a volume of .347 L at 6680 mmHg and 27°C?
Answer:0.124 mol- I think not completely positive on it
Explanation:6680⋅mm⋅Hg is not a realistic measurement of pressure....
I assume you mean 6680⋅mm⋅Hg/760⋅mm⋅Hg⋅atm^-1 = 8.79⋅atm.
And we use the Ideal Gas Equation:
n=PV/RT=8.79⋅atm×0.347⋅L/0.0821⋅L⋅atm⋅K−1⋅mol−1×300⋅K=0.124⋅mol
If a plant has a total of 17g of carbon dioxide and water reacting in photosynthesis, then how much glucose and oxygen will the plant produce?
A. 8.5g
B. 34g
C. 17g
(Take your time)
Answer:
Basically it would be 8.5g. Not total sure.
Explanation:
If its right plz give brainlest.
Answer:
A. 8.5g
Explanation:
Have a great day!
What product of an acid-base reaction is an ionic compound?
A. A salt
B. Water
C. A metal
O D. A gas
SUBMIT
Answer:
Salt
Explanation:
Answer: A gas
Explanation: Contrary to popular belief, it is not salt. Salt can be separated from water.
PLS HELPPP!!!!!!!!!!!
Answer:
c
Explanation:
ionic bonds; cations (metals) GIVE electrons to anions (nonmetals)
As you move from the top to the bottom of the periodic table
Answer:
From top to bottom down a group, electronegativity decreases. This is because atomic number increases down a group.
Answer:
From top to bottom down a group, electronegativity decreases. This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.
Explanation:
10. (a) Describe how the structure of an alloy is different to a pure metal
You can type directly into this text box below: (2)
10. (b) Suggest why coins are not made of pure copper. Do not give cost as a reason.
You can type directly into this text box below: (1)
Grade 5+ 15 marks
Total 27 marks
Um, yea, please help lol
How many moles are in 3.45g of KCI ?
0.0463 mol KCl
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
3.45 g KCl
Step 2: Identify Conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of Cl - 35.45 g/mol
Molar Mass of KCl - 39.10 + 35.45 = 74.55 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 3.45 \ g \ KCl(\frac{1 \ mol \ KCl}{74.55 \ g \ KCl})[/tex]Multiply/Divide: [tex]\displaystyle 0.046278 \ mol \ KCl[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
0.046278 mol KCl ≈ 0.0463 mol KCl
what is PH??
i will mark as brainlest for best answer
Explanation:
pH is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions are measured to have lower pH values than basic or alkaline solutions. The pH scale is logarithmic and inversely indicates the concentration of hydrogen ions in the solution.
How many moles of sucrose
are in 5.25x1029 sucrose
molecules?
Answer:
872093.02moles
Explanation:
Given parameters:
Number of atoms of Sucrose = 5.25 x 10²⁹atoms
Unknown:
Number of moles = ?
Solution:
To solve this problem, we must understand that a mole of any substance contains the Avogadro's number of particles.
6.02 x 10²³ atoms makes up 1 mole of an atom
5.25 x 10²⁹ atoms will contain = [tex]\frac{5.25 x 10^{29} }{6.02 x 10^{23} }[/tex] = 872093.02moles
student plans to isolate chlorophyll, mix it in a solution of carbon dioxide and water, and then shine light on the mixture. Do you predict glucose will be produced inside the mixture
Answer:
No
Explanation:
In order for glucose to be produced inside the mixture, photosynthesis has to take place. The photosynthetic process requires a series of steps within an organelle called the chloroplast. The chloroplast contains the chlorophyll and other enzymes that are necessary for photosynthesis.
Once the chlorophyll is isolated, it becomes separated from the enzymes necessary for the completion of photosynthesis, and the process is truncated. When light is shined on the mixture, the majority would instead be lost as heat while some cause the chlorophyll molecules to glow.
What units are used to measure mass and weight?
Answer: Milligrams ,grams ,kilograms ,quintals, tons
Explanation: Hope this helps
How many atoms are in 5.76 moles of aluminum?
Answer:The number of atoms in 2.0 mole Al is A. 2.0 Al atoms. B. 3.0 x 1023 Al atoms.
Secondly, is aluminum an atom or molecule? Aluminum is the second element in the thirteenth column of the periodic table. It is classified as a post-transition metal and a "poor metal". Aluminum atoms contain 13 electrons and 13 protons. There are 3 valence electrons in the outer shell.