a. The unit cell is the smallest group of atom which have overall symmetry of a crystal, and from which is the entire letters can be buled built up by repetition in 3 dimensions.
b. The volume(v) of the unit cell is equal to the cell edge length (a)cubed.
c. density of polonium is 9.32g/cm3.
Which of the following increases with increasing atomic
number down a group?
Answer:
The number of energy levels increases as you move down a group as the number of electrons increases. Each subsequent energy level is further from the nucleus than the last. ... The outermost electrons are repelled by the inner shell electrons (Screening effect) and hence, the atomic size increases.
Explanation:Increase in atomic size
Whenever the same two elements form more than one
compound, the different masses of one element that combine
with the same mass of the other element are in the ratio of
small whole numbers.
TRUE
FALSE
Answer:
The answer is true
Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.
which body system carries oxygen, glucose and amino acids to all the cells of the body?
Answer:
Blood
Explanation:
This flows through the body so it gives it all over.
PLS help!!!!!!!!
Why are halogen atoms never a central atom?
Answer:
They can’t have more than 8 valence electrons.
Explanation:
Question in picture!!!!!!
Answer:
6 atoms
Explanation:
______ bonds form when 2 metal atoms share electrons.
Which of the following elements has 3 electrons in the 2p sublevel?
O A. O
O B. C
O C. B
O DN
Answer:
the answer is D. N
AP3X
According to electronic configuration, there are 3 electrons in the 2p sublevel ,hence the correct option is D.
Electronic configuration is defined as the distribution of electrons that are present in an atom or molecule in an atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is important for understanding the structure of periodic table. It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions so as to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in their ground state and hence are said to be stable.
Thus, the correct option is D.
Learn more about electronic configuration,here:
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How and why was the periodic table set up?
Which of these solutions are basic at 25 °C ? A:[OH−]=2.53×10−7 M B:[H3O+]=9.99×10−9 M C:[H3O+]=6.31×10−4 M
Answer: frfg6
Explanation: 655tyyt
What mass in grams of MgSO4 is required to make 59.3 mL of 2.68 M
solution?
Answer:
Approximately [tex]19.1\; \rm g[/tex].
Explanation:
Number of moles of formula units of magnesium sulfate required to make the solutionThe unit of concentration in this question is "[tex]\rm M[/tex]". That's equivalent to "[tex]\rm mol \cdot L^{-1}[/tex]" (moles per liter.) In other words:
[tex]c(\mathrm{MgSO_4}) = 2.68\; \rm M = 2.68\; \rm mol \cdot L^{-1}[/tex].
However, the unit of the volume of this solution is in milliliters. Convert that unit to liters:
[tex]\displaystyle V = 59.3\; \rm mL = 59.3 \; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.0593\; \rm L[/tex].
Calculate the number of moles of [tex]\rm MgSO_4[/tex] formula units required to make this solution:
[tex]\begin{aligned}n(\rm MgSO_4) &= c \cdot V \\ &= 2.68 \; \rm mol \cdot L^{-1} \times 0.0593\; \rm L \approx 0.159\; \rm mol \end{aligned}[/tex].
Mass of magnesium sulfate in the solutionLook up the relative atomic mass data of [tex]\rm Mg[/tex], [tex]\rm S[/tex], and [tex]\rm O[/tex] on a modern periodic table:
[tex]\rm Mg[/tex]: [tex]24.305[/tex].[tex]\rm S[/tex]: [tex]\rm 32.06[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Calculate the formula mass of [tex]\rm MgSO_4[/tex] using these values:
[tex]M(\mathrm{MgSO_4}) = 24.305 + 32.06 + 4 \times 15.999 \approx 120.361\; \rm g \cdot mol^{-1}[/tex].
Using this formula mass, calculate the mass of that (approximately) [tex]0.159\; \rm mol[/tex] of [tex]\rm MgSO_4[/tex] formula units:
[tex]\begin{aligned}m(\mathrm{MgSO_4}) &= n \cdot M \\&\approx 0.159 \; \rm mol \times 120.361 \; \rm g \cdot mol^{-1} \approx 19.1\; \rm g\end{aligned}[/tex].
Therefore, the mass of [tex]\rm MgSO_4[/tex] required to make this solution would be approximately [tex]19.1\; \rm g[/tex].
HELP
What type of bond is formed between the carbon and either oxygen in CO2?
A) Single
B) Double
C) Triple
A 12 gram piece of Cu at 475 oC is placed in contact with a 15 gram piece of Cr at 265 oC.
Assume the two pieces of metal are the system and that there is no heat exchange between system and surrounding.
What is the final temperature of the two pieces of metal expressed in degree C?
Answer:
349.22°C
Explanation:
Let the final temperature of the two pieces of metal be x.
Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.
The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.
Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.
Thus;
q_lost = q_gain
Where;
q_lost = m1•c1•Δt1
q_gained = m2•c2•Δt2
Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.
From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C
We are given;
m1 = 12g and m2 = 15g
Thus;
12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)
2194.5 - 4.62x = 6.9x - 1828.5
6.9x + 4.62x = 2194.5 + 1828.5
11.52x = 4023
x = 4023/11.52
x = 349.22°C
How many moles are there in 256 g of silicon
please help 10 points asap
Answer:
opposite
Explanation:
Answer:
opposite
Explanation:
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How much heat would be required to convert 5.31 mol of a pure substance from a liquid at 40.0°C to a gas at 113.0°C?
Answer:
Q = 7.7 KJ
Explanation:
The complete question carries the following data:
Specific Heat Capacity of Liquid State = C(l) = 1.45 J/mol.°C
Specific Heat Capacity of Gaseous State = C(g) = 0.65 J/mol.°C
Boiling Temperature = Tb = 88.5°C
Heat of Vaporization = ΔH(vap) = 1.23 KJ/mol
Now, first we calculate the heat required (Q₁) to raise he temperature to boiling point:
Q₁ = n*C(l)*ΔT₁
where,
n = no. of moles = 5.31 mol
ΔT₁ = Temperature difference from 40°C to Tb = 88.5°C - 40°C = 48.5°C
Therefore,
Q₁ = (5.31 mol)(1.45 J/mol.°C)(48.5°C)
Q₁ = 373.4 J = 0.37 KJ
Now, we calculate the heat required (Q₂) to change its phase:
Q₂ = nΔH(vap)
Q₂ = (5.31 mol)(1.23 KJ/mol)
Q₂ = 6.53 KJ
Now, we calculate the heat required (Q₃) to raise he temperature to boiling point:
Q₃ = n*C(g)*ΔT₃
where,
n = no. of moles = 5.31 mol
ΔT₃ = Temperature difference from Tb to 113°C = 113°C - 88.5°C = 24.5°C
Therefore,
Q₃ = (5.31 mol)(0.65 J/mol.°C)(24.5°C)
Q₃ = 84.5 J = 0.08 KJ
So, the total heat required to convert 5.31 mol of this pure substance from a liquid at 40°C to a gas at 113°C is:
Q = Q₁ + Q₂ + Q₃
Q = 0.37 KJ + 6.53 KJ + 0.08 KJ
Q = 7.7 KJ
The total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.
The given parameters;
molar heat capacity of liquid, C(l) = 1.45 J/mol.⁰Cmolar heat capacity of gas, C(g) = 0.65 J/mol.⁰CThe total heat required to convert the pure substance from liquid to gas at the given temperature is calculated as follows;
[tex]Q = nc_l \Delta \theta + nc_g \Delta \theta \\\\ \Delta \theta = (113 - 40) = 73^0 C \\\\Q = (5.31 \ mol \times 1.45 \frac{J}{mol .\ ^0C} \times 73\ ^0C) + (5.31 \ mol \times 0.65 \frac{J}{mol .\ ^0C} \times 73 \ ^0C)\\\\Q = 814 \ J[/tex]
Thus, the total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.
"Your question is not complete, it seems to be missing the following information;"
How much heat would be required to convert 5.31 mol of a pure substance from a liquid at 40.0°C to a gas at 113.0°C? (molar heat capacity of liquid, C(l) is 1.45 J/mol.⁰C and molar heat capacity of gas, C(g) is 0.65 J/mol.⁰C).
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The net force on a vehicle that is accelerating at a rate of 1.5m/s^2 is 1,800 newtons. What is the mass of the vehicle to the nearest kilogram?
Answer:
Explanation:
Net force F = 1800 N
acceleration a = 1.5 m /s²
mass = m
mass = force / acceleration
= 1800 / 1.5
m = 1200 kg
The mass of the vehicle to the nearest kilogram is 1200 Kg
The force acting on an object is defined by the following equation
Force (F) = mass (m) × Acceleration (a)
F = ma
With the above formula, we can obtain the mass of the vehicle as follow:
Force (F) = 1800 N
Acceleration (a) = 1.5 m/s²
Mass (m) =?[tex]m = \frac{F}{a} \\ \\ m = \frac{1800}{1.5} \\ \\ m = 1200 \: Kg[/tex]
Therefore, the mass of the vehicle is 1200 Kg
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If the stack of bricks on the right has a mass of 240 kg, approximately what is the mass of the stack of bricks on the left?
A.
2400 kg
B.
720 kg
C.
320 kg
D.
480 kg
Answer:
720
Explanation: study island
Answer:
720
Explanation:
An atom has 8 protons, 8 neutrons and 9 electrons. is thus a cation, anion, or neutral atom?
Answer:
It is an Anion because there are more electrons than protons making it negative
C is the element symbol for which element?
a. Carbon
b. Cadmium
c. Celenium
d. Chlorine
Answer:
A) Carbon
Explanation:
the others are wrong its A
Answer:
A) carbon
Explanation:
carbon or simply c has an atomic number of 6 and it has an atomic mass of 12.01 amu. it belongs to group 4a
The atom is one of the basic units of matter. Which part of the atom mostly determines the size of the atom?
a.Electrons
b.Nucleus
c.Neutrons
d.Protons
Answer:
Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. The separation that occurs because electrons have the same charge. The number of protons in the nucleus. The core electrons in an atom interfere with the attraction of the nucleus for the outermost electrons.
Explanation:
That would be B I believe, but please correct me if I'm wrong.
I need the answer multiple choice
Answer:
it's answer is
element of an atom ✌️
which type of rection has the general formuial ab+cd
PLEASE HELP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Which of the following does NOT increase with increasing temperature?
a kinetic energy
b thermal energy
c potential energy
d none of the above
Answer:
Explanation:
Potential energy
Calculate the time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) on a cathode.
Answer:
632.7 secs
Explanation:
Equation of the reaction:
Tl^3+ + 3e ------> Tl
If 1F = 96500 C
Q= It
Where;
I= current
t= time
3× 96500 C deposited 204 g of Tl
0.868 × t deposited 0.387 g of Tl
3 × 96500 × 0.387 = 204 × 0.868 × t
t= 3 × 96500 × 0.387/ 204 × 0.868
t= 632.7 secs
The time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) is 2689 s
We'll begin by calculating the quantity of electricity needed to deposit 0.387 g of Ti
Ti³⁺ + 3e —> Ti
Recall:
1 mole of Ti = 48 g
1 electron (e) = 96500 C
Thus,
3 electrons = 3 × 96500 = 289500 C
From the balanced equation above,
48 g of Ti was deposited by 289500 C of electricity.
Therefore,
0.387 g of Ti will be deposited by = (0.387 × 289500) / 48 = 2334.09375 C of electricity
Finally, we shall determine the time required.Quantity of electricity (Q) = 2334.09375 C
Current (I) = 0.868 A
Time (t) =?t = Q / I
t = 2334.09375 / 0.868
t = 2689 sTherefore, the time required for the reaction is 2689 s
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A rock rolls down a hill. Which form of energy is this an example of?
Chemical
Electrical
Mechanical
Thermal
Answer:
Mechanical
Explanation:
chemical
Explanation:
I took test 2020
17. Which is a fat-soluble vitamin?
O vitamin B
O vitamin C
O vitamin A
Will give brainliest, Look at the graph above. Compare it to the periodic table. What do you notice about the location on the periodic table of the elements that represent the high points
Answer:
We can see that the atomic radius decreases across every row.
Explanation:
I will comment more below.
The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.
The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.
Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.
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why saturated fatty acid can’t create kink ?
How many joules are released when 30.0 g of H2O(g) condenses at 100°C?
Answer:
-6.78 × 10⁴ J
Explanation:
When water condenses (goes from the gaseous state to the liquid state) it releases energy in the form of heat. We can calculate this heat using the following expression.
Q = ΔH°cond × m
where,
Q is the heat released
ΔH°cond is the latent heat of condensation (ΔH°cond of water is -2260 J/g)
m is the mass
Q = ΔH°cond × m
Q = -2260 J/g × 30.0 g
Q = -6.78 × 10⁴ J
TRUE OR FALSE QUESTIONS
1) ___________________________ The physical properties of metals include
dullness, malleability, ductility, and conductivity.
2) ___________________________ Neutrons have a negative charge.
3) ___________________________Mendeleev was known as the father of the
periodic table.
1: FALSE The physical properties of metals include shininess, malleability, ductility, and conductivity.
2: FALSE Neutrons are the particles in an atom that have a neutral charge. They aren't positive like protons. They aren't negative like electrons.
3: TRUE Dmitri Ivanovich Mendeleev was a Russian chemist and inventor. He is best remembered for formulating the Periodic Law and creating a farsighted version of the periodic table of elements. He is also known as the "father of the periodic table"
Answer:
1.T, 2.F., 3.T
Explanation:
2 is false because electrons have a negative charge neutrons have no charge