Answer:
4.2 × 10¹⁷ atoms of Se
Explanation:
Step 1: Convert the mass to grams
We will use the conversion factor 1 g = 10⁶ μg.
55 μg × 1 g/10⁶ μg = 5.5 × 10⁻⁵ g
Step 2: Calculate the moles corresponding to 5.5 × 10⁻⁵ g of Se
The molar mass of Se is 78.96 g/mol.
5.5 × 10⁻⁵ g × 1 mol/78.96 g = 7.0 × 10⁻⁷ mol
Step 3: Calculate the atoms in 7.0 × 10⁻⁷ moles of Se
We will use Avogadro's number: there are 6.02 × 10²³ atoms of Se in 1 mole of Se.
7.0 × 10⁻⁷ mol × 6.02 × 10²³ atom/1 mol = 4.2 × 10¹⁷ atom
What science should i take in highschool? (Biology,Chemistry,Physics)
Answer:
Biology
Explanation:
I'm currently taking highschool biology right now and it's a lot of fun. If you like animals and cells, a lot of fun.
How many atoms are contained in 5.77 grams of aluminum? Express your answer in exponential notation (Ex: 6.02*1023 would be entered as 6.02e23). Round the digits to the hundredths place. No units required.
Answer:
5.09
Explanation:
True or False (+2 Points Possible each): Write true if the statement is true. If false, replace
the underlined word with the correct word in the space provided.
1. Radiation is the transfer of energy through space.
2. Molten rock rises in Earth's mantle caused by gravity.
3. Fossils provide evidence of sea-floor spreading.
4. Older, denser Earth material sinks below younger material
known as subduction.
5. Convergent boundaries
move plates towards each other
mountains.
is
forming
PLEASE HELP ASAP THIS IS DUE BY MIDNIGHT!
Answer:
2. Molten rock rises in Earth's mantle caused by (pressure)
Explanation:
i think i just had a similar question
What is known as the amount of
mass in a given volume?
Answer:
Density
Explanation:
Density is a measure of how much mass is contained in a given volume
What gases were in the second atmosphere? *
Answer:
Second Earth's Atmosphere
The second atmosphere, which was the first to remain with the earth, was created by volcanic outgassing and comet ice. There was a lot of water vapor, carbon dioxide, phosphorus, and methane in this atmosphere, but absolutely no oxygen.
Explanation:
Giving away 20 points and brainlest, please help
What type of transport does not require energy to move molecules across the plasma membrane?
A. bilayer
B. active
C. passive
D. concentration gradient
Answer:
A
Explanation:
Answer:
I don’t think that A is the correct answer, I believe that C may be the correct answer
Explanation:
which element has the lowest atomic mass in group 6A
Number of unpaired electrons in the electronic configuration 1s2 2s2 2p4 is
Answer:
2 electrons
Explanation:
What particles are contained in the nucleus of an atom?
O electrons & protons
O neutrons & electrons
O neutrons & protons
O pixels & electrons
Match the subatomic particle to its best explanation:
PHOTON
a fermion
b composite particle
c weak force
d strong force
e forces
f leptons
g up
h +2/3
i gravity
Answer:
a
Explanation:
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Worth 15 points
I need help plssss first answer is brainliest
Answer:
sodiom i think
Explanation:
0. Earth's rock is continually cycling through different states and locations. The diagram below shows the rock cycle. The labels for two processes are missing.
Weathering of
ROCKS at surface
IGNEOUS
ROCK
Uplin
SEDIMENTARY ROCK
METAMORIHIC ROCK
Melting
Which of these processes could be happening at the stage labeled 2?
o folding and mountain building
chemical changes due to heat and pressure
compaction and cementation of weathered sediments
subduction of an oceanic plate beneath a continental plate
Answer:
Chemical changes due to heat and pressure
Explanation:
Just took the test, hope this helps! :)
Answer:
Chemical changes due to heat and pressure
Explanation:
I took this test and got a 100%! :D
Please help!!!
True or False: A physical property is a property of a substance that can be observed or measured without changing the chemical identity of the substance.
True? Or False?
Answer:True
Explanation:
Compared to atoms of metals, atoms of nonmetals generally
A)have higher electronegativities
B)have lower first ionization energies
C)conduct electricity more readily
D)lose electrons more readily
Compared to atoms of metals, atoms of nonmetals generally conduct electricity more readily. Therefore, option C is correct.
What are metal atoms ?The term metal atom is defined as an atom of an element that exhibits typical metallic properties, being typically shiny, with high electrical and thermal conductivity.
Metallic bonds form when the charge is spread over a greater distance than the size of individual atoms in solids. Most left elements in the periodic table form metallic bonds, such as zinc and copper.
Metals are defined as elements to the left of the line. Elements just to the right of the line have both metal and nonmetal properties and are referred to as metalloids. Nonmetals are elements at the far right of the periodic table.
Thus, option C is correct.
To learn more about the metal atom, follow the link;
https://brainly.com/question/1675378
#SPJ2
Write the balanced equation for the following.
Answer:
it forms copper hydroxide crystals
Explanation:
NaOH(aq)+CuSO4(aq)=Cu(OH)2(s)+Na2SO(aq)
What two processes occur at the mid ocean ridge?
Answer:
ridge push and slab pull
Explanation:
there are two processes through to be responsible for the spreading seen at mid ocean ridges and there is some uncertainty as to which is dominant. ridge push occurs when the weight of the ridge pushes at the rest of tectonic plate away from the ridge often towards a subduction zone. hope this helped
Na+CL2=2NACL is the balanced reaction for the formation of table salt. Given 20 grams of Na and 10 grams of Cl2, which reactant is in excess? How much NaCL should be produced from these amounts of the two reactants?
Excess reactant : Na
NaCl produced : = 16.497 g
Further explanationGiven
Reaction(balanced)
2Na + Cl₂⇒ 2NaCl
20 g Na
10 g Cl₂
Required
Excess reactant
NaCl produced
Solution
mol Na(Ar = 23 g/mol) :
= 20 : 23 = 0.87
mol Cl₂(MW=71 g/mol):
= 10 : 71 g/mol = 0.141
mol : coefficient :
Na = 0.87 : 2 = 0.435
Cl₂ = 0.141 : 1 = 0.141
Limiting reactant : Cl₂(smaller ratio)
Excess reactant : Na
Mol NaCl based on mol Cl₂, so mol NaCl :
= 2/1 x mol Cl₂
= 2/1 x 0.141
= 0.282
Mass NaCl :
= 0.282 x 58.5 g/mol
= 16.497 g
Lithium Nitride is a ionic bonded compound because?
5. Geologists think that the inner and outer cores of Earth consist of
iron and nickel.
Answer:
is this true/false? if so its true.
Explanation:
Which ion forms the strongest ionic bond with a given anion?
Answer:
Explanation:
A cation with a 2+ charge will make a stronger ionic bond than a cation with a 1+ charge. A larger ion makes a weaker ionic bond because of the greater distance between its electrons and the nucleus of the oppositely charged ion.
Some students believe that teachers are full of hot air. If I inhale 2.1 liters of gas at a temperature of 200 C and it heats to a temperature of 370 C in my lungs, what is the new volume of the gas?
Answer:
2.86L
Explanation:
Given parameters:
V1 = 2.1L
T1 = 200°C = 200 + 273 = 473K
T 2 = 370°C = 370 + 273 = 643K
Unknown:
V2 = ?
Solution:
Since pressure is constant, we apply the Charles's law;
[tex]\frac{V1}{T1}[/tex] = [tex]\frac{V2}{T2}[/tex]
V is volume
T is the temperature
1 is the initial state
2 is the new state
[tex]\frac{2.1}{473}[/tex] = [tex]\frac{V2}{643}[/tex]
V2 = 2.86L
what does mechanical digestion mean ?
Answer:
Explanation:
Mechanical digestion involves physically breaking down food substances into smaller particles to more efficiently undergo chemical digestion. The role of chemical digestion is to further degrade the molecular structure of the ingested compounds by digestive enzymes into a form that is absorbable into the bloodstream.
25 points !!!!!!
a 10 ml sample of borax- borate equilibrium solution reacts completely with 23.33 ml of a 0.1006 M HCl solution. calculate the concentration of borate and then the Ksp for borax
Answer:
See answer below
Explanation:
To do this, you need to write down the chemical reaction giving place here.
As this is to explain the thermodynamics of the borax-borate reaction, the general reaction is as follow:
Na₂B₄O₅(OH)₄.8H₂O(s) <---------> 2Na⁺(aq) + B₄O₅(OH)₄²⁻(aq) + 8H₂O(l)
Where:
Na₂B₄O₅(OH)₄.8H₂O(s) = Borax
B₄O₅(OH)₄²⁻(aq) = Borate ion
Now, in order to calculate the concentration of borate, this compound undergoes a titration with HCl. The reaction that takes place here is:
B₄O₅(OH)₄²⁻(aq) + 2HCl + 3H₂O <---------> 4H₃BO₃(aq) + 2Cl⁻(aq)
According to this reaction, it takes 2 moles of HCl to completely react with the borate ion, therefore, the expression to calculate the concentration will be:
2 nHCl = nB₄O₅(OH)₄²⁻
2M₁V₁ = M₂V₂
Replacing the data of concentration and volume of both compounds we have:
2 * 0.1006 * 23.33 = 10M₂
M₂ = 2 * 0.1006 * 23.33 / 10
M₂ = 0.4693 M
This is the concentration of the borate. Now, to calculate the Ksp we need to write the equilibrium reaction taking place with the borax:
Na₂B₄O₅(OH)₄.8H₂O(s) <---------> 2Na⁺(aq) + B₄O₅(OH)₄²⁻(aq) + 8H₂O(l)
Ksp = [B₄O₅(OH)₄²⁻] [Na⁺]²
As we already have the concentration of borax, we can also know the concentration of sodium. If we call concentration as "s" (Stands for solubility), and rewrite the expression of Ksp:
Ksp = s * (2s)²
Finally, replacing the value of the concentration we have:
Ksp = (0.4693) (2*0.4693)²
Ksp = 0.4693 * 0.881
Ksp = 0.4134
Hope this helps
What are two sources of phosphorous?
A. stratosphere
B. Erosion
C. Cows
D. Fossil fuels
E. Fertilizer
Answer:
A. stratosphere
E. Fertilizer
Explanation:
how many atoms are in 26g of cobalt
this is due today so please help me
Answer:
b north to south
Explanation:
what does group 16 (oxygen family) have in common
Answer: here is your answer
Explanation:
The oxygen family consists of the elements that make up group 16 on the periodic table: oxygen, sulfur, selenium, tellurium, and polonium. These elements all have six electrons in their outermost energy level, accounting for some common chemical properties among them.
Answer:
they all have 6 valence electrons
Explanation:
all elements in group 16 have 6 valence electrons
Can someone hel me On these questions please
Answer:
B, A, A
Explanation:
What is the % of water in (MgSO4 . 2H2O)?
Answer: A hydrate is found to have the following percent composition: 48.8% MgSO4 and 51.2% water.
Explanation:
i dont know
shorthand representation of compounds
The skeletal formula, also called line-angle formula or shorthand formula, of an organic compound is a type of molecular structural formula that serves as a shorthand representation of a molecule's bonding and some
Answer:
The skeletal formula, also called line-angle formula or shorthand formula, of an organic compound is a type of molecular structural formula that serves as a shorthand representation of a molecule's bonding and some details of its molecular geometry.
Explanation:
hope this helps