Answer:
D) 10.812
Explanation:
Given:
The two isotopes of boron (B).
Boron-10 has an abundance of 19.8% and Boron -11 has an abundance of 80.2%
To find:
The atomic mass of europium.
Solution:
Mass of Boron-10 = 10.013 amu
The percentage abundance of Boron-10 = 19.8%
The fractional abundance of Boron-10 =0.198
Mass of Boron-11 = 11.009 amu
The percentage abundance of Boron-11= 80.2%
The fractional abundance of Boron-11= 0.802
The average atomic mass of Boron = A.M
A.M = Mass of isotope x Fractional abundance of isotope
= 10.013amu x 0.198 +11.009amu x 0.802 = 10.81u
Therefore, D) 10.812 amu is the atomic mass of boron.
Which elements are present in all organic compounds? 1. Hydrogen and oxygen 2. Nitrogen and Carbon 3. Nitrogen and oxygen 4. Hydrogen and Carbon
Answer:
my answer is num:3 Hydrogen and oxygen.
204,900,000,000
How many significant digits are found?
Answer:
4
Explanation:
There are 4 significant figures because when there is not a decimal, then only numerical values over 0 are counted. So the numbers counted in sig figs are 2049, and none of the other 0s.
So if it was 204,900,000,000.0, then it would have 12 significant figures.
What element is in period 4 and is in group 18
Answer:
Krypton is the element
Symbol: Kr
what kind of reaction is happening when glaze is fired
Answer:
Oxidation and Reduction occurs
Explanation:
pls help ASSSAPPPP!!!!
Answer:
b or d
Explanation:
Answer:
The answer is B (it's reactivity)
What are the atoms of Fe(SCN)3
Answer:
55.845
Explanation:
yep
why does a higher concentration make a reaction faster?
Answer:
Explanation: because more is always better
the positon of hydrogen is conversial in mendleevs perodic table give reason
Answer:
the position of hydrogen is controversial in periodic table because hydrogen is the only element with out neutron. it belongs to 1 st group but it is not placed there .
Explanation:
What does the graph show about the rate of temperature change over time?
Answer:
The temperature is the same overtime.
Explanation:
Since the line on the graph is straight the temperature will be constant.
PLEASE HELP!!
What kind of metal is Co?
Alkali Metal
Transition Metal
Alkaline Earth Metal
Answer:
I believe Cobalt is a Transition Metal.
Answer:
answer is transition metal
What is the speed of an object that travels 20 meters in 5
Answer:
5 what
Explanation:
not enough information
What type of intermolecular bond may form between na and br
Answer:
Ionic
Explanation:
Na is a metal and Br is a non-metal. Makes an ionic bond. Hope that helps
What is the molecular mass of Br 2?
Answer:
159.808 g/mol
Answer:
159.80 g/mol
Explanation:
79.90×2=159.80g/mol
What is the formula for Water?
Name full name element's name
Answer:
2 Hydrogen atoms and 1 Oxygen atoms makes water
Explanation:
Hope this helps^^
Answer: Its chemical formula H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms,
Explanation: i hopes it helps :)
An atom of radium (Ra) forms a monatomic ion.
Which ion does it most likely form?
a- Ra2-
b- Ra-
c- Ra2+
d- Ra+
Answer:
The atomic number of the element Radium (Ra) is 88. It is an alkaline earth metal. Electronic configuration of Radium (Ra) will be [Rn]7s^{2}[Rn]7s
2
It belongs to the group IIA of the periodic table. Alkaline earth metals that belong to the group IIA of the periodic table lose the valence electrons to form a +2 ion.
Therefore, Radium with an electronic configuration of [Rn]7s^{2}[Rn]7s
2
will lose the two 7s electrons to form the cation with +2 charge.
what is the pattern of liquids and solids from the center of the earth out
Explanation:
I'm sorry if this doesn't answer this correctly but solid liquid solider solid liquid/solid
in an oxidation-reduction reaction, how is the reducing agent changed?
Explanation: The additional terminology comes from the definition that, within redox processes, a reductant transfers electrons to an oxidant; hence, the reductant (reducing agent) loses electrons, so is oxidized, while the oxidant (oxidizing agent) gains electrons, so is reduced.
In an oxidation-reduction reaction, the reducing agent loses electrons and loses potential energy, Therefore, option (C) is correct.
What is a reducing agent?A substance that loses its electrons in a redox reaction to other substances and gets oxidized is called a reducing agent. A reducing agent is one of the reactants which reduces the other reactant by donating the electrons to the reactant of an oxidation-reduction reaction.
If the reducing agent can't pass electrons to another reactant in a reaction, then the reduction process does not occur and the reaction cannot proceed.
In redox reactions, when an electron loses potential energy as a result of the transfer and energy is released. Electrons with more potential energy are associated with less electronegative atoms and less potential energy is associated with a more electronegative atom (such as O).
Therefore, the reducing agent loses electrons and loses potential energy in a redox reaction.
Learn more about reducing agent, here:
https://brainly.com/question/15584308
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Your question is incomplete, but probably the complete question was,
In an oxidation-reduction reaction, how is the reducing agent changed?
(A) it gains electrons and gains potential energy
B) it gains electrons and loses potential energy
C) it loses electrons and loses potential energy
D) it loses electrons and gains potential energy
for the sn1 reaction, draw the major organic product, identify the nucleophile, substrate, and leaving group, and determine the rate limiting step.
C4H9OH is the substrate, Br- is the nucleophile and H2O is the leaving group.
In an SN1 reaction, the rate limiting step is the formation of the carbocation. The carbocation is formed as water which is the leaving group departs. After the leaving group departs, the nucleophile (Br-) attacks to yield the major organic product. The protonation of the -OH group is the first step in the reaction.
It then follows that, C4H9OH is the substrate, Br- is the nucleophile and H2O is the leaving group.
Learn more: https://brainly.com/question/22824409
Pls help!!! for 100 points, please only answer if your actually going to help ! A kitten has a mass of 1582 g and accelerates at 1.7 m/s^2. What is the net force acting upon the kitten?
Write down all the givens from the problem.
Are all of the units in the form required to use the generic equation? If not, then show your conversion.
Write the generic equation (equation with variables only) for this problem. Do not add any spaces between letters or symbols.
Substitute your numbers into the generic equation. This is where you show your math work, step by step. Solve the problem
Enter the numeric portion (numbers only) of your answer here rounded to the nearest tenth.
Enter the numeric portion (numbers only) of your answer here rounded to the nearest tenth.
Answer:
2689.4
Explanation:
Please help me with chem, it would be very appreciated!
why it is necessary to draw a Lewis diagram before predicting the shape of a molecule
To determine the shapes of molecules, we must become acquainted with the Lewis electron dot structure. Although the Lewis theory does not determine the shapes of molecules, it is the first step in predicting shapes of molecules. The Lewis structure helps us identify the bond pairs and the lone pairs.
Please mark BRAINLIEST.
Someone pls help me I will make you brain
Match them pls
Answer:
Explanation:
Carbon monoxide → Prevents oxygen from being transported in the body
Nitrogen oxides → Can cause asthma
Particulate matter → Irritates lungs, dizziness, seizures, or death
Sulfur oxides → Inflammation and irritation of the respiratory system
I hope this helps!
The nucleus of most atoms is composed of which of the following sub-atomic particles?
A. tightly packed protons.
B. tightly packed neutrons.
C. tightly packed protons and neutrons.
D. loosely connected protons and electrons.
Answer:
C. Tightly packed protons and neutrons
Explanation:
It consists of two sub-atomic particle namely proton and neutron.
This dense nucleus is responsible for most of the mass of atom.
Answer:
C. tightly packed protons and neutrons
Explanation:
The nucleus of an atom is made of protons and neutrons with electrons orbiting the nucleus.
Examine the models shown above.where is potential energy the greatest
Answer:
A
Explanation:
Because it is the greatest
Water, made of 1 oxygen atom bonded with 2 hydrogen atoms, is what
Answer:
It is a water molecule.
Explanation:
A water molecule consists of two atoms of hydrogen linked by covalent bonds to the same atom of oxygen. Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.
Answer:
A water molecule is an example of a molecule created through covalent bonding. Water is made up of one oxygen atom and 2 hydrogen atoms, hence the chemical symbol H2O. A hydrogen atom is made up of 1 proton at its core and 1 electron that revolves around the core in a three-dimensional orbit.
Explanation:
During chemical reactions__________are broken and___________to form
new substances with different properties, but mass is still_____________ .
Answer:
1st blank : Atoms
2nd blank : Reactants
I'm still trying to find the 3rd blank. I'll put it in comments if I find it
Explanation:
Hope this helps :)
Pls make brainliest :}
And have an amazing day <3
Someone pls help me I will make you brain
Answer:
i cant read it but its c and a
Explanation:
my thinking faces
why does the total volume of water and alcohol decrease when the liquids were mixed together?
Answer: I think the alcohol molecules slip between the water molecules and take up that space, so you have less that you started with.
Explanation:
Is it possible to have an electromagnetic wave with a wavelength (a) of 104.68 m and an energy of 3.25 x 10-27 J? Show your work.
2. You work for an environmental company as an environmental toxicologist and have been hired to determine the contaminant present in a local resident’s pool. Create a flow chart outlining how you would detect the possible presence of Fe2+ and/or Sr2+
Explain why graphite conducts electricity.
Answer in terms of the structure and bonding in graphite.
Answer:
Diamond has a giant molecular structure. Each carbon atom is covalently bonded to four other carbon atoms. A lot of energy is needed to separate the atoms in diamond. This is because covalent bonds are strong, and diamond contains very many covalent bonds.
Graphite on the other hand has flat layers of carbon atoms held by weak van der Waal's forces which makes Graphite a weak object and easily breakable.
As graphite contains layers of carbon atoms. The layers slide over each other easily because there are only weak forces between them, making graphite slippery. These electrons can move through the graphite, carrying charge from place to place and allowing graphite to conduct electricity.One valence electron of each carbon atom remains free, Thus making graphite a good conductor of electricity. Whereas in diamond, they have no free mobile electron. Hence there won't be flow of electrons That is the reason behind diamond are bad conductor electricity.These electrons are free to move between the layers in graphite, so graphite can conduct electricity.The forces between the layers in graphite are weak. This means that the layers can slide over each other.
How many grams of Hydrogen (H) would need to react with 143 grams of Oxygen (O) to make 235 grams of Water (H20)? 235
Answer:
45 grams
Explanation: