Answer:
FALSE
Explanation:
they were much more diverse
Which of the following is considered a sign of a chemical change?
How long will it take for 500.0g of radium decay to 2.0g
How many moles are in 5.25 X 10 25
atoms of Au?
Answer:
The answer is 87.21 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{5.25 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 87.2093023...[/tex]
We have the final answer as
87.21 molesHope this helps you
Diffusion of Ammonia in an Aqueous Solution. An ammonia (A)-water (B) solution at 278 K and 4.0 mm thick is in contact at one surface with an organic liquid at this interface. The concentration of ammonia in the organic phase is held constant and is such that the equilibrium concentration of ammonia in the water at this surface is 2.0 wt 'Yo ammonia (density of aqueous solution is 991.7 kg/m3) and the concentration of ammonia in water at the other end of the film 4.0 mm away is 10 wt % (density of 961.7 kg/m3). Water and the organic are insoluble in each other. The diffusion coefficient ofNH3 in water is 1.24 x 10- 9 m 2/sCalculate the flux N_B. Explain.
Answer:
The Flux N_B = 0
Explanation:
So, we are given the following set of data or parameters which is going to help in solving this particular Question. So, let us take each at a time;
=> "An ammonia (A)-water (B) solution at 278 K and 4.0 mm thick is in contact at one surface with an organic liquid at this interface."
=>" 2.0 wt 'Yo ammonia (density of aqueous solution is 991.7 kg/m3) and the concentration of ammonia in water at the other end of the film 4.0 mm away is 10 wt % (density of 961.7 kg/m3). ''
With the information above, we can determine the N_A(which the question did not specify that we should calculate).
For the value of N_B, it will be equals to zero(0) because the insolubility of water in organic solvent.
What are two properties of most nonmetals
Answer: Summary of Common Properties
High ionization energies.High electronegativities.Poor thermal conductors.Poor electrical conductors.Brittle solids—not malleable or ductile.Little or no metallic luster.Gain electrons easily.Dull, not metallic-shiny, although they may be colorful.Explanation:
May I please have brainiest?
Answer:
The two properties of most non metals are high ionization energy and poor electrical conductivity. The correct option among all the options that are given in the question is option "1". In general it is known that nonmetals are very poor conductors of heat and electricity. The nonmetals that are solid are normally very brittle and has very little or no metallic luster at all. Nonmetals are highly reactive and show variety of chemical properties. It can also be pointed out that the nonmetals gain electrons very easily.
brainliest pleaseee :)
Calculate the average atomic mass of unknown element X. You determine that isotope 127X makes up 80%, isotope 126X makes up 17%, and isotope 128X makes up 3%.
A. 127.10 amu
B. 126.86 amu
C. 127.54 amu
D. 126.20 amu
Answer:
Option B. 126.68 amu
Explanation:
The following data were obtained from the question:
Isotope A (¹²⁷X):
Mass of A = 127
Abundance (A%) = 80%
Isotope B (¹²⁶X):
Mass of B = 126
Abundance (B%) = 17%
Isotope C (¹²⁸X):
Mass of C = 128
Abundance (C%) = 3%
Average atomic mass of element X =.?
Th4 average atomic mass of X can be obtained as follow:
Average atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(127 × 80)/100] + [(126 × 17)/100] + [(128 × 3)/100]
= 101.6 + 21.42 + 3.84
= 126.68 amu
Therefore, the average atomic mass of X is 126.68 amu
A 0.2027 gram sample of finely powdered limestone (mainly CaCO₃) was dissolved in 50 mL of 0.1035 M HCl. The solution was heated to expel CO₂ produced by the reaction. The remaining HCl was then titrated with 0.1018M of NaOH and it required 16.62 mL. Calculate the percentage of CaCO₃ in the limestone sample? CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O
Answer:
Explanation:
CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O
100 gm + 2000 mL of M HCl
Amount of HCl remaining = .1018 M of 16.62 mL
= .1018 x 16.62 mL of M HCl
= 1.69 mL of M HCl
Initial HCl taken = 50 mL of .1035 M HCl
= 5.175 mL of M HCl
HCl reacted = 5.175 - 1.69 mL of M HCl
= 3.485 mL of M HCl
2000 mL of M HCl reacts with 100 gm of CaCO₃
3.485 mL of M HCl will react with .174 grams of CaCO₃
percentage of calcium carbonate = .174 x 100 / .2027
= 85.84 %
The ___ has many functions; one is to regulate growth.
Growth hormon somatotropin
describe the purpose of using a chemical equation.
Answer:
The purpose of using a chemical equation is to keep track of elements and the number of atoms of each of the elements on each side of the equation. ... They use symbols and formulas to show the chemical reaction so that chemical names do not need to be written out.
Answer:
:0
Explanation:
Sample Response: Chemical equations show how chemicals interact when a reaction occurs. They use symbols and formulas to show the chemical reaction so that chemical names do not need to be written out. They also help keep track of all elements and the number of atoms of each element on each side of the equation.
pls help ill mark you as brainliest
Answer:
Explanation:
Synthesis- D
Combustion- C
Decomposition- A
Single Displacement- C
Double Displacement- B
PLZ HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
Reactivity
Explanation:
Luster. Ductile, and Malleabillity are all physical.
Explain why the several different types of microscopes are all necessary.
Answer:
some zoom in farther
Explanation:
some microscopes zoom in farther than others so we can see even smaller things
Order the masses from smallest to largest
Can someone please tell me if this right.
Answer:
1. 7.86 × 10⁴ g
2. 7.86 × 10⁴ kg
3. 1.989 × 10¹³ mg
4. 1.989 × 10²⁸ kg
5. 1.989 × 10³³ g
Explanation:
The easiest way to make sure you have the right answer is to convert all units to the same unit.
A. 1.989 × 10¹³ mg = 1.989 × 10¹⁰ g
B. 7.86 × 10⁴ g
C. 1.989 × 10³³ g
D. 7.86 × 10⁴ kg = 7.86 × 10⁷ g
E. 1.989 × 10²⁸ kg = 1.989 × 10³¹
The correct order is B < D < A < E < C
An increase in which of the following would increase the boiling point of a
liquid?
Answer:
The boiling point increases with increased pressure up to the critical point, where the gas and liquid properties become identical.
what is potiential and kinetic engergy? pls someone answer my question
Answer:
Potential Energy is stored energy or energy of position (gravitational). The object isn't moving. For example, a ball being held is potential energy because the object isn't moving but it has the potential of turning into kinetic energy.
Kinetic Energy is the energy of motion. For example, running. You are moving, and there is clear action and activity
Energy stored in an object due to its position is Potiential energy . Energy that is moving object has due to its motion is Kinetic energy .
4
The element bromine at room temperature is a liquid with a density of 3.12 g/nl.
Calculate the mass (wanted measurement) of 125 mL (given measurement) of bromine.
(use the given density as the conversion factor to calculate the wanted measurement).
Sign out
What will the coefficients be for the following balanced equation? (a) N2 + (b) H2 → (c) NH3
Answer:
his reaction is the synthesis of Ammonia using Nitrogen and Hydrogen gas.
N
+
H
→
N
H
3
We must remember that Nitrogen and Hydrogen are both diatomic molecules in their standard gas form. This adjusts the equation to
N
2
+
H
2
→
N
H
3
Now we need to adjust coefficients in order to balance the atoms on each side of the equation. Currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.
We can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.
N
2
+
3
H
2
→
2
N
H
3
This gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.
I hope this was helpful.
Explanation:
Answer:
1N2 + 3H2 →2NH3
Explanation:
Plato answer
#8- please help i suck at this, ill mark brainliest
Answer:
A. Synthesis
B. Combustion
C. Single-replacement
D. Decomposition
Explanation:
A: Synthesis. Two reactants are combined to form, or synthesize, one product.
B: Combustion. This is the general reaction for combustion. When something combusts, oxygen must be present. Carbon dioxide and water must also be produced.
C: Single-replacement. The oxygen from Fe₂O₃ is moved to K to form K₂O. Only one thing is being moved, or replaced.
D: Decomposition. You have one compound that breaks into, or decomposes, into two products.
Please choose the best description, or definition of Faunal Succession.
principle stating that specific groups of organisms lived and died within a specific
time frame due to the ice age
principle stating that specific groups of fawns lived in a specific region and are
found in the rocks shoing fawns onl live in specific areas.
principle stating that specific layers of the earth have contain fauna of different
types showing biodiversity.
rinciple stating that specific groups of organisms have followed, or succeeded.
one another in a definite sequence through Earth history
Answer:
Principle stating that specific groups of organisms have followed, or succeeded one another in a definite sequence through Earth history
Explanation:
Principle stating that specific groups of organisms have followed, or succeeded one another in a definite sequence through Earth history describe Faunal succession because it is a principle that indicate that fossil plants and animals succeed each other in a sequential manner even if they occur in different places. Successive strata and faunas are linked together to form composite section in the Earth's history.
Answer:
the last one
Explanation:
Can an Atom be broken down into a smaller substance? Yes or No Explain.
Answer:
Yes
Explanation:
A atom is made out of 3 elements, protons which are positive charges, electrons which are negative charges that swirl around the atom, and a neutron with a neutral charge. The nucleus of the atom is basically the center of the atom.
Plz help! :) :D I will mark you as BRAINLIEST for the best answer!!! ( I actually mean it)
Physical and Chemical Properties of Magnesium
Here is an EXAMPLE of how it has to be like. Instead of Mercury, you HAVE to do Magnesium
Physical Properties of Mercury: ”I’m a highly stable element, so you can count on me”
Chemical Properties of Mercury: ”I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon”
Assume that the pendulum clock shown in the photograph is a closed
system
Which statement describes evidence that the pendulum's energy is conserved
even as it eventually stops moving?
A. Energy must be added to the pendulum to keep it from slowing
down
B. Some of the clock's matter is transformed into new energy
C. The amount of each type of energy in the system can be
measured
D. All its mechanical energy is transformed into other forms of
energy
Answer:
Explanation:
d
Answer:
D. All it’s mechanical energy is transformed into other forms of energy.
Explanation:
I got it right
?
The group number tells the number of
Elements in the column
Number of valence electrons
O Number of energy levels
O Number of protons in the elements
Answer:
number of valence electrons
Explanation:
elements in the same group has same number of valence electrons
How many moles of gold, a U, are in 3.60×10^-5 G of gold?
Answer:
See Below.
Explanation:
This is a conversion problem:
Using the molar mass of Gold (given in a periodic table) which is 196.97g/mol
you have
[tex](3.60*10^-5 g) *\frac{1moles}{196.97g}[/tex]
you always arrange the equation in a way to cancel whatever you don't want (grams) and leave what you do want (moles). Here grams cancel (top and bottom), so you're left with:
[tex]\frac{(3.60*10^-5 g) *(1)}{196.97} = 1.83*10^-7[/tex] moles of Gold
Joe bought a roll of gray duct tape containing 5400 inches. If there are 5280 feet in a mile, how
many miles long is Joe's roll of duct tape?
Answer:
STANDARD: 0.085 mi, 450 ft, or 150 yds
METRIC: 0.137 km, 137.16 m, or 13716 cm
Explanation:
Classify the following reactions and complete the given below
A) NaCl + AgNO3 - NaNO3 + AgCl
Answer:
chemical equation balance.
Explanation:
if you need more explanation , comment.
Which of the following elements has the largest electronegativity? A) Bismuth B) Nitrogen C) Potassium D) Arsenic
Which types of reactions would result in the formation of precipitate?
Answer:
Double Displacement Reaction
Explanation:
A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.
Answer question number 3
A hypothetical element has two main isotopes with mass numbers of 59 and 62. If 73.00% of the isotopes have a mass number of 59 amu, what atomic weight should be listed on the periodic table for this element? Answer in units of amu.
since 73% of the isotope is given, take 100%-73% to get the remaining % of the isotopes which is going to be 27%.
hence,
atomic weight= (73×59) + (27×62)
=4307+1302
=5609 amu