Answer:
Newton discovered it.
Explanation:
Gravity is the attraction between the earth and any object. and gravitational force is the attraction between any two objects.
Answer:
gravity is a force that pulls things towards each other
Explanation:
issac newton is the one who discovered it
Assume that the total volume of a metal sample is the sum of the volume occupied by the metal ions making up the lattice and the (separate) volume occupied by the conduction electrons. The density and molar mass of the first metal are 911 kg/m3 and 27.7 g/mol, respectively; assume the radius of an ion is 97.3 pm. (a) What percent of the volume of a sample of this metal is occupied by its conduction electrons
Answer:
92.4%
Explanation:
The volume per cubic meter of sodium preoccupy by the sodium ions is
[tex]V_{Na} = n \times V[/tex]
where;
volume (V) of each Na atom = [tex]\dfrac{ 4}{3} \pi r^3[/tex]
Radius of each ion = 97.3 pm = 97.3 × 10⁻¹²
no.of atoms in the sample n = mass of the sample / ( molar mass / NA)
mass of the sample per cubic metre = 911 kg/m³
∴
[tex]V = \bigg [ \dfrac{4}{3} \pi r^3 \bigg ] \bigg [\dfrac{MN_A}{m} \bigg ][/tex]
[tex]V = \bigg [ \dfrac{4}{3} \pi (97.3 \times 10^{-12} )^3 \bigg ] \bigg [\dfrac{ (911 kg/m^3 (m^3))(6.023\times 10^{23})}{27.7 \times10^{-3}\ kg/mol } \bigg ][/tex]
V = 0.07643 m³
The fraction of available conduction electrons are;
= (1 - V)
= 1 - 0.07643
= 0.92357
≅ 92.4%
Which of the following statements is true about exothermic reactions?
Answer:
An Exothermic Reaction , gives off more heat, and a little energy to its surroundings.
this can helps us figure out that the answer is , C, More heat is given off into its products.
Explanation:
which of the following could be classified as producing a physical change?
what is the balanced equation for naphthalene and sulphur?
napthalene: C10H8 sulphur: S02
Explanation:
C10H8
a wooden block with a mass of 2.0kg starts from at the top of an inclined plane and ends with a force of 25N at the bottom what was the rate of acceleration of the block
Answer:
Force F = 20N .
Mass m = 2.0 kg
Initial velocity u = 0
acceleration, a = 10m/s
2
t = 1 sec.
Now Refer to the attachment, See the free body diagram of the block.
Force works on the block:-
Weight, W = mg
W = 2 × 10
W = 20N (which is Downward)
Normal force N = mg cos37
N = 20 × 0.80
N = 16 N. (perpendicular & upward to the plane )
Here Applied Force, P = 20N (which is down along the plane)
Now For Final Speed, We know the formula:-
v = u + at
v = 0 + 10 × 1
v = 10 m/s
the Distance travelled s = ut + 0.5 at×t
s = 0 + 0.5 ×10×1×1
s = 5 m.
Now,
(a) So work done by the force of gravity in 1 sec. = F × d
⇒20 N × 5m
⇒100 J.
(b) Here the weight act as downward, so distance travelled in downward.
⇒5 × sin37
⇒5 × 0.6
⇒3 m.
so work done by gravity,
⇒20 N × 3 m
⇒60 J.
(c) Now, work done by all the forces
⇒change in Kinetic energy
⇒
2
1 m(v2
−u 2
)
⇒0.5×2.0×(10 2
−0 2 )
⇒ 100 J.
⇒W.D by frictional force
= work was done by all forces -( work was done by Normal force + work done by applied force + work done by gravity )
= 100 J - (100 + 60 +0 )
= 100 - 1
Hope this helps you≅
1) How many moles are in 4.0x10^24 atoms?
Answer:
6.64 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{4 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 6.644518...[/tex]
We have the final answer as
6.64 molesHope this helps you
How many atoms are in a sample containing 4.000 moles of carbon?
A)6.022 x 10
23
atoms
B)2.408 x 10
24
atoms
O
24
C)7.233 x 10 atoms
D)2.893 x 10
25
atoms
Answer:
c I think but that's only what i think
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
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. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
number of atoms/molecules/ formula units of carbon= number of moles of carbon × 6.022×10²³
number of moles of carbon= 4 moles
substituting all the given values in the above equation, we get
number of atoms/molecules/ formula units of carbon= 4 × 6.022×10²³
number of atoms/molecules/ formula units of carbon=2.4088×10²⁴ atoms of carbon
There are 2.4088×10²⁴ atoms of carbon
Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
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An ideal gas sample is confined to 3.0 L and kept at 27 °C. If the temperature is raised to 77 °C and the initial pressure was 1500 mmHg, what is the final pressure?
The gas is confined in 3.0 L container ( rigid container) ⇒ the volume remains constant when the temperature is increased from from 27oC to 77oC and therefore V1=V2 .
Hope it helps you please mark as brainlistIdeal gas law is valid only for ideal gas not for vanderwaal gas. Ideal gas is a hypothetical gas. Vanderwaal gas can behave as ideal gas at low pressure and high temperature. Therefore the final pressure is 1,750 mmHg.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of gas
V= volume of gas
n =number of moles of gas
T =temperature of gas
R = Gas constant = 0.0821 L.atm/K.mol
At constant volume, the above equation can be rearranged as
P₁/T₁ = P₂/T₂
Substituting all the given values in the above equation, we get
1500 ÷300= P₂÷350
P₂ =1,750 mmHg
Therefore the final pressure is 1,750 mmHg.
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Giselle is working with a chemical substance in a laboratory. She observes that when the chemical is heated, it gives off a gas. She assumes that the gas is oxygen but decides to test this assumption to verify it. Which type of scientific knowledge is Giselle’s assumption? A. fact B. hypothesis C. law D. observation E. theory
Answer:
The correct answer is B. Hypothesis
Explanation:
Consider the equation:
4Al + 3O2 = 2Al2O3
Is this equation balanced? Why or why not?
The equation is balanced. There are 4 aluminium atoms and 6 oxygen atoms on each side.
find the number of hydrogen atoms of an alkyl group with 2 carbon atoms if n=2
Answer:
5
Explanation:
An alkyl group is a functional group that contains only hydrogen and carbon atoms. It has the general formula: CnH2n+1.
Since n=2, plug it into the formula.
C2H2(2)+1
=
C₂H₅
Hope that helps.
An s orbital has how many orientations? Group of answer choices
Answer:
One orientation
Explanation:
A s orbital is a sphere like shape that surrounds the atomic nucleus that consists of electrons that can be found at the highest or lowest region of the orbital. S orbitals only consist of "one orientation" and is commonly mistaken by the p orbital because the p orbital also consists of electrons that can be found the most.
Hope this helps.
What are the rules for writing
names/formulas for ionic
compounds? Give examples
where you need to produce
the formula from the name
AND the name from the
formula. Make sure to
include examples of
transition metals and
polyatomic ions.
How many
electrons does Oravetium contain
A gas is brought to a final pressure of 6.8 atm. after increasing its temperature from 40 K to 280 K. Calculate the original pressure of the gas.
Answer:
0.97 atm.
Explanation:
From the question given above, the following data were obtained:
Final pressure (P2) = 6.8 atm
Initial temperature (T1) = 40 K
Final temperature (T2) = 280 K
Initial pressure (P1) =?
Thus, we can obtain the initial (original) pressure of the gas as follow:
P1/T1 = P2/T2
P1 /40 = 6.8/280
Cross multiply
P1 × 280 = 40 × 6.8
P1 × 280 = 272
Divide both side by 280
P1 = 272/280
P1 = 0.97 atm
Therefore, the original pressure of the gas is 0.97 atm.
At which point is crust neither created nor destroyed?
island chain
mid-ocean ridge
divergent boundary
transform boundary
Answer:
transform battery
Explanation:
Answer: D. Transform Boundary
Explanation: I did the test.
Explain how atomic
radius, valence electrons
and effect nuclear charge
creates the trend for metal
reactivity.
Answer:A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.
Answer:
A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels increases, so there is a greater distance between the nucleus and the outermost orbital.Explanation:
5 A snowball sits at the top of the hill. Which of the following changes will increase the kinetic energy of the snowball? A Additional snow falls on the snowball, increasing its mass. B The snowball is pushed and rolls down the hill, gaining speed. The weather warms and the snowball melts, decreasing its mass. D The snowball is moved and now sits on a hill that is higher.
Answer:
B
Explanation:
it is B because in order to have kinetic energy the object has to be in motion, because if it wasnt in motion and sitting on the hill then it has potentail energy, hope this helps
what is a common use for electromagnets
Answer:
Electromagnets are widely used as components of other electrical devices, such as motors, generators, electromechanical solenoids, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment.
Explanation:
Hope this helps :)
(didn't get this from the internet)
What is the atomic number of this atom?
6
8
9
16
The atomic number of this atom : 8
Further explanationGiven
Atomic model (attached)
Required
The atomic number
Solution
To determine the atomic number of an element, we can look at the number of electrons or the number of protons, because
atomic number = number of protons = number of electrons in neutral atoms
While the mass number is the number of neutrons + the number of protons located in the atomic nucleus
The charge of each of these atomic sub particles:
electron: charge -1proton: charge +1neutron: not charged / 0If we look at this atomic model, there are 8 electrons in the shell, consisting of 2 electrons in the first shell and 6 electrons in the second shell (which can also be called valence electrons)
Whereas in the atomic nucleus there are 8 protons and 10 neutrons
Answer:8
Explanation:
4. Kendrick drags his bat out to play baseball. which statement best describes the science of what he did?
O Kendrick would use less energy if he dragged the bat faster.
Kendrick did not have to work to move the bat because he dragged it.
Kindrick gave the bat potential energy.
Kindrick gave the bat kinetic energy.
Explanation:
Kendrick gave the bat potential Energy
Which chemical equation below is not balanced?
- 3 MgSO4 + 2 Nag PO4 → Mgs (PO4),+3 Na, S04
- 2 NaOH + HNO, → NaNO, + 2 H,0
- CH12 O6 4 6O2 → 6 CO, + 6 H,0
- HBr AGNO, → HNO, + AgBr
pic if needed ;)
Answer:
B
Explanation:
The second one is not balanced correctly.
2 NaOH + 2HNO3 → 2NaNO3 + 2 H20
I didn't notice this before but it can be balanced without the twos.
NaOH + HNO3 → NaNO3 + H20
It was still wrong. It needed to have the twos removed, not 2 more added. Adding two more isn't wrong, but it should be balanced without 2s if at all possible.
What kind of reactions tend to be spontaneous?
O A. Reactions that are endothermic
B. Reactions that are exothermic
C. Reactions that decrease in entropy
D. Reactions that increase in enthalpy
The spontaneous reactions are said to be exothermic in nature. Hence, option B is correct.
What is a spontaneous reaction?The type of reaction that has not been utilizing energy input output to the reaction system in order to favor the formation of product are termed as exothermic reaction.
The entropy has been the tendency of the randomness of atoms in the system, and the enthalpy has been the energy of the system.
With the spontaneous reaction, there has been an increase in the entropy of the system with the formation of the products, and a decrease in the enthalpy. The reaction forms no use of the input energy, and thereby cannot be endothermic in nature.
Therefore, the reaction that is exothermic tends to be spontaneous reactions. Hence, option B is correct.
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1s2 3s2 3p6 3s2 3p6 3d6 4s2 what is element
The element with the electron configuration, 1s2 3s2 3p6 3s2 3p6 3d6 4s2, will be iron.
Atomic number and electronic configurationsIn the electronic configuration of elements, the number of electrons possessed by the element is shared into the orbitals according to their energy levels.
The electrons are first shared in orbitals in the same energy level before pairing starts.
Also for neutral atoms, the number of electrons is equivalent to the number of protons. The number of protons in itself represents the atomic number of elements.
Thus, considering this electron configuration, 1s2 3s2 3p6 3s2 3p6 3d6 4s2; the total number of electrons in all the orbitals is 26. The element with the atomic number of 26 is iron.
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Which process is constructive?
A:Water wears away rocks in a river.
B:Wind removes sand from a beach.
C:volcano forms an island in the ocean.
D:An earthquake breaks apart a cliff on a mountain.
Would a highly conductive, malleable, and lustrous solid be a metal, nonmetal, or metalloid?
The molar solubility of CaSO4 in water is 0 .67 gram per liter of solution. Calculate the Ksp.
Answer:
Ksp = 2.4 * 10⁻⁵
Explanation:
The equation for the dissolution and dissociation of CaSO4 in water is given as: CaSO₄ ---> Ca²⁺ + SO₄²⁻
The expression for the Ksp of the dissociation equation above is:
Ksp = [Ca²⁺] [SO₄²⁻]
The molar ratio of the dissociated ions and the solute is 1 : 1, this means that every 1 mole of CaSO₄ that dissolves produces 1 mole of Ca²⁺ and SO₄²⁻ each
The molar solubility of a substance is the number of moles that dissolve per liter of solution.
molar solubility of CaSO₄ = number of moles /liter of solution
number of moles of CaSO₄ = mass/molar mass
molar mass of CaSO₄ = 136 g/mol
number of moles of CaSO₄ = 0.67/136 = 0.0049 moles
molar solubility of CaSO₄ = 0.0049 mol/ 1 L = 4.9 * 10⁻³ moles per liter
therefore, molar solubility of CaSO₄ = 4.9 * 10⁻³
Ksp = (4.9 * 10⁻³) (4.9 * 10⁻³)
Ksp = 2.4 * 10⁻⁵
Answer:
2.4 * 10^-5
Explanation:
Molar solubility of CaSO4 = 0 .67 g/L/136 g/mol = 4.9 * 10^-3 Mol/L
Given that;
CaSO4(s) -------> Ca^2+(aq) + SO4^2-(aq)
Hence, Ksp = [Ca^2+] [SO4^2-]
Where [Ca^2+] =[SO4^2-]=s
Ksp = s^2
since s = 4.9 * 10^-3 Mol/L
Ksp = (4.9 * 10^-3 Mol/L)^2
Ksp = 2.4 * 10^-5
in which type of bond are electron shared between atoms?
A. ionic
B.covalent
C.metallic
Does iron always have a charge of 2+ when it forms an ion
Answer:
Roman numeral notation indicates charge of ion when element commonly forms more than one ion. For example, iron(II) has a 2+ charge; iron(III) a 3+ charge.
Explanation:
1. (solution/solvent/solute) Use the correct word in the following sentence:
dissolved in
makes up a
2 What is the difference between a strong electrolyte and a weak electrolyte?
3. The solubility of sodium chlorate in water is 52g/100g H20. If 0.46 moles of sodium
chlorate are dissolved in 60g of water, is this solution
saturated/supersaturated/unsaturated?
Answer:
1. solute dissolved in solvent makes up a solution.