Answer:
B. Na and Li
Both are group I elements.
Which is the lowest energy level having “d” orbitals?
Answer:
n=3 the minimum n for which d orbital exist.
What is the “Island of Stability”?
Answer:
The island of stability is a term from nuclear physics that describes the possibility of elements with particularly stable "magic numbers" of protons and neutrons. This would allow certain isotopes of some transuranic elements to be far more stable than others, that is, decay much more slowly.
Explanation:
Identify the missing particle in the following nuclear equation.
aPlatinum-199
bMercury-198
cMercury-199
dPlatinum-198
Answer:
c
Explanation:
Mass of 2×10^21 number of atoms of an element is 0.4g. What is the mass of 0.5 mole of the element?
Answer:
66.7 g
Explanation:
Number of atoms = 2×10²¹
Mass of 2×10²¹ atoms = 0.4 g
Mass of 0.5 moles of that element = ?
Solution:
1 mole contain 6.022×10²³ atoms
2×10²¹ atoms × 1 mol / 6.022×10²³ atoms
0.33×10⁻² mol
0.003 mol
0.003 mole have mass of 0.4 g
0.5 mol have mass 0.5/0.003×0.4 g = 66.7 g
1- What is the mass of 5.5 mole of sodium?
2- How many moles in 230 grams of water?
3- What is the mass of 4.5 mole of lithium chloride?
4- How many moles in 750 grams of sodium chloride?
Answer:
1. 126.44 or 126.4
2. 12.766 or 12.8
3.190.77 or 190.8
4.12.833 or 12.8
Explanation:
Can y’all help me with this question How many atoms are found in the chemical formula below Al2( SiO3)2
Answer:
the answer is 10
Explanation:
Al2 is 2 atoms by itself
(SiO3)2 is 8 because Si is a single atom and O3 is 3 oxygen atoms but because of the subscript outside of the parentheses it doubles and becomes 2 and 6 respectively
write a skeletal equation for the following reaction: An aqueous solution of barium nitrate and an aqueous solution of sodium sulfate are mixed together. Then balance the completed chemical equation.
Answer: skeletal equation : [tex]Ba(NO_3)_2(aq)+Na_2SO_4(aq)\rightarrow NaNO_3(aq)+BaSO_4(s)[/tex]
The products are sodium nitrate and barium sulphate.
balanced equation : [tex]Ba(NO_3)_2(aq)+Na_2SO_4(aq)\rightarrow 2NaNO_3(aq)+BaSO_4(s)[/tex]
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The skeletal equation is:
[tex]Ba(NO_3)_2(aq)+Na_2SO_4(aq)\rightarrow NaNO_3(aq)+BaSO_4(s)[/tex]
The balanced chemical equation is:
[tex]Ba(NO_3)_2(aq)+Na_2SO_4(aq)\rightarrow 2NaNO_3(aq)+BaSO_4(s)[/tex]
Which statement best explains why cells separate and expel waste?
Answer:
I would say the 2nd one It helps growth and repair of cells of orgasmsBut your school would probably say the 3rd one It helps remove toxins from the body to maintain homeostasisExplanation:
2. Our cells produce a lot of waste that must be eliminated (excreted) from the body. These residues are called excreta. The residues formed from the chemical reactions that take place inside the cells can be eliminated through:
• of the respiratory system (carbon dioxide)
• skin (sweat)
urinary system (urine)
Our cells expel these substances to maintain the dynamic balance (homeostasis) of our body and promote our well-being.
Aluminum has density of 2.7g/cm3.
What is the mass of 35 cm3 aluminum in g?
Answer:
density= 2.7 g/cm3
volume= 25 cm3
mass = density× volume
= 35×2.7
= 94.5 g
how much °f of 35°C ?
help me please
Answer: 95 degrees fahrenheit hope this helps :]
Explanation:
what is chemical reaction?
Answer:
a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction
how much potassium bromide will form a saturated solution with 100 grams of water at 40 degrees celsius
Answer:
75.4 g.
Explanation:
Hello there!
In this case, since the solubility stands for the maximum amount of a solute that is completely dissolved in a specific amount of solvent, typically 100 g of water as the universal solvent; we need to take into account that the higher the temperature the higher the solubility for the most of the solids.
In such a way, since the solubility of potassium bromide at 20 °C is 65.3 g per 100 g of water, at 40 °C is 75.4 g per 100 g of water, proving the aforesaid. Therefore, 75.4 g of potassium bromide will form a saturated solution with 100 g of water at 40 °C.
Regards!
! 20 points !need answer FAST!
In nuclear reactions, how can huge amounts of energy be produced?
A. By converting chemical energy into nuclear energy
B. By releasing thermal energy in uranium
C. By creating energy from the surrounding space
D. By destroying matter to create energy
Answer:
C.
Explanation: In nuclear fission and fusion reactions, some of the energy in matter is converted to energy. If you weigh the reactants and the products, the products will weigh less than the reactants. This is called the mass defect and is the result of turning matter into energy.
Answer:
D.
Explanation:
With the Fat Boy and Little Boy nuclear bombs that were drop on Japan, They used a little gun (inside the bomb) that shot a little slug. this hit and caused a chain reaction that caused the bomb to detonate. This released much energy. Destroying much of the two cities when the bombs were dropped.
A. Energy is transferred to different forms
B. Energy can be destroyed in different forms
C. Energy is created
D. Energy is released during a combustion
Answer:
A. Energy is transferred to different forms .
Explanation:
Hello!
In this case, we need to consider the law of conservation of mass and energy which states that mass and energy cannot be neither created nor destroyed, just modified; it means we can rule out B. and C. so far.
Moreover, since D. is actually true for combustion reactions because they are used to provide energy in industrial operations, this is not the concern here because a combustion reaction is not considered.
Therefore the correct option is A. Energy is transferred to different forms as the energy provided by Rose is transferred to the pendulum system .
Best regards!
Density of gold is 19.3g/cm^3 what is the density in lbs/in^3 units
The density in lbs/in³ units : 0.697
Further explanationGiven
Density of gold is 19.3 g/cm³
Required
Conversion to lbs/in³
Solution
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
Conversion factor
1 g = 0,00220462 lbs
1 cm³ = 0,0610237 in³
So the density :
[tex]\tt 19.3~\dfrac{g}{1~cm^3}\times \dfrac{cm^3}{0.0610237~in^3}\times \dfrac{0.00220462~lbs}{1~g}=0.697~lbs/in^3[/tex]
I need help with science. picture attached
Answer:
there is no picture.
Explanation:
What is radiative equilibrium?
Answer:
Radiative equilibrium is the condition where the total thermal radiation leaving an object is equal to the total thermal radiation entering it. It is one of the several requirements for thermodynamic equilibrium, but it can occur in the absence of thermodynamic equilibrium.
Answer:
Radiative equilibrium is the condition where the total thermal radiation leaving an object is equal to the total thermal radiation entering it. It is one of the several requirements for thermodynamic equilibrium, but it can occur in the absence of thermodynamic equilibrium.
Hope this helps :)
One way to account for the mass "lost" in a reaction that involves a gas would be to________.
Answer:
Place the experiments on a scale
Explanation:
If you place two of the same experiments on a scale, and cover one with a cup, the one with the cup will "lose" mass, while the other won't, due to the cup being a "containment field" I guess you could call it.
Chemistry
Definition in your own words
Will check if you got it from online.
Word: Phase change
Answer:
See explanation.
Explanation:
Hello!
In this case, considering the concept of phase change, we understand that it is related how the phases of matter, solid, liquid and gas, are related to each other for a specific substance.
For instance, when going over water, we notice that its most common phase at this atmospheric conditions is the liquid phase; however, if it starts losing energy (being cooled down) its molecules tend to get together and freeze, undergoing a phase change to solid. On the other hand, if heated up, its molecules will be able to get farther to each other and therefore undergo a phase change to gas.
Thus, we can realize that a phase change is also explained molecularly; because when a substance undergo a phase change, its molecules rearrange, according to the addition or removal of energy and therefore get to another phase.
Best regards!
What is matter? Choose the best answer.
A Anything that is solid
B Anything that takes up space
C Anything that has a fixed volume
D Anything that can be seen
Answer:
B
Explanation:
list 3 things that make the index contour unique
Answer:
htoybuuo
t857 NJ n8
u. t i ukuo. jl
Which of the following is a chemical weathering agent?
1.) acid produced by plants growing on rocks
2.) growing tree roots
3.) burrowing animals
4.) ice wedging
PLEASE HELP ME FAST ASAP
Answer:
1. acid produced by plants growing on rocks
plz give me BRAINLIEST answer
I NEED HELP REALLY BAD AND THIS IS DUE IN 5 MINSSS
The successive ionization energies for a given element are listed. How many valence electrons does it have?
Answer:
5
Explanation:
The number of valence electrons in the atom is 5 as can be seen from the ionization energy.
Ionization energy is the measure of the readiness of an atom to lose an electron. The lower the value the easier it is for an atom to lose an electron and vice versa.
After the removal of the first electron it becomes increasingly more difficult to remove succeeding electrons because of the imbalance between the positive nuclear charge and the remaining electrons.Therefore, since we have 5 ionization energies given, the number of valence electrons in this atom is 5.
What's the charge on Ni in the compound NiCi3? *
+1
+2.
+3
- 7
-2.
3
you can't tell
Answer:
+3
Explanation:
Chlorine is anion with a -1 charge. But they are three chlorine atoms.
-1 * 3 = -3
So they have a -3 charge.
So to balance the compound, the nickel has to be a cation with a +3 charge.
-3 + 3 = 0
Furthermore, a chemical bond always has a 0 charge. Remember that.
Hope it helped! Rate my answer a 5 star if correct.
what is the pressure of the dry gas alone ?
P O₂ = 736.2 torr
Further explanationGiven
P tot=760 torr
P H₂O = 23.8 torr
Required
P gas/O₂
Solution
Dalton's law of partial pressures stated that
the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases
Can be formulated:
P tot = P1 + P2 + P3 .... Pn
P tot = P H₂O + P O₂
760 torr = 23.8 torr + P O₂
P O₂ = 760 - 23.8
P O₂ = 736.2 torr
When solutions of acetic acid and sodium hydroxide react, which of the following are not present in the net ionic equation?
I. hydrogen ion
II. acetate ion
III. sodium ion
IV. hydroxide ion
A) I and II.
B) I, II, and III.
C) I and IV.
D) I and III.
E) II and III.
Answer:
E) II and III.
Explanation:
Let's consider the complete ionic equation when solutions of acetic acid and sodium hydroxide react. It includes all the ions and molecular species.
CH₃COO⁻(aq) + H⁺(aq) + Na⁺(aq) + OH⁻(aq) ⇒ CH₃COO⁻(aq) + Na⁺(aq) + H₂O(l)
The net ionic equation includes only the ions that participate in the reaction and the molecular species.
H⁺(aq) + OH⁻(aq) ⇒ H₂O(l)
The species not present are:
II. acetate ion
III. sodium ion
What is the balanced, net ionic equation for the reaction shown below?
Pb(NO3)2(aq) + H2SO4(aq) + PbSO4(s) + 2 HNO3(aq)
The net ionic equation :
Pb²⁺(aq)+SO₄²⁻(aq) ⇒ PbSO₄(s)
Further explanationGiven
Reaction
Pb(NO3)2(aq) + H2SO4(aq) + PbSO4(s) + 2 HNO3(aq)
Required
The net ionic equation
Solution
The equation of a chemical reaction can be expressed in the equation of the ions
In the ion equation, there is a spectator ion that is the ion that does not change (does not react) because it is present before and after the reaction
When these ions are removed, the ionic equation is called the net ionic equation
For gases and solids including water (H₂O) can be written as an ionized molecule
Ionic equation :
Pb²⁺(aq)+ 2NO₃⁻(aq) + 2H⁺(aq)+SO₄²⁻(aq) ⇒ PbSO₄(s) + 2H⁺(aq)+NO₃⁻(aq)
2NO₃⁻(aq) + 2H⁺(aq) ⇒ a spectator ions
The net ionic equation :
Pb²⁺(aq)+SO₄²⁻(aq) ⇒ PbSO₄(s)
The net ionic equation is Pb²⁺(aq)+SO₄²⁻(aq) ⇒ PbSO₄(s)
The given equation is
Pb(NO3)2(aq) + H2SO4(aq) + PbSO4(s) + 2 HNO3(aq)
Writing its ionic equation
Pb²⁺(aq)+ 2NO₃⁻(aq) + 2H⁺(aq)+SO₄²⁻(aq) ⇒ PbSO₄(s) + 2H⁺(aq)+NO₃⁻(aq)
Now the ionic equation contains spectator ions that do not react. They are present in both the reactant and the product. When these ions are removed, the ionic equation is called the net ionic equation.
2NO₃⁻(aq) + 2H⁺(aq) ⇒ a spectator ions
The net ionic equation is:
Pb²⁺(aq)+SO₄²⁻(aq) ⇒ PbSO₄(s)
Learn more:
https://brainly.com/question/19046605
Which of the following statements about sidestream smoke is not true?
a. It is the smoke that a smoker inhales from a cigarette.
b. It is dirtier and has a different chemical makeup than mainstream smoke.
c. It is the smoke that people around the smoker inhale.
d. It is the smoke that results from the burning end of a cigarette.
Answer: a
Explanation: the smoker actually exhales the sidestream smoke
Which of these reservoirs contains the most water?
Answer:
Glaciers
Explanation:
Reservoirs refers to paces where water are stored. The largest water reservoir on earth are the oceans which contain about 97% of all the water on the earth.
The next highest reservoir are the glaciers or the polar ice caps. These hold quite an enormous amount of the water found on earth.
Surface and other fresh water only account for about 1.2% of all the surface water on earth.Ground water accounts for a very minute percentage of the water found on earth.
0.72-mol sample of is put into a 1.00-L vessel and heated. At equilibrium, the vessel contains 0.40 mol of and 0.40 mol of . Calculate the value of the equilibrium constant for the decomposition of to and at this temperature.
Answer:
0.50
Explanation:
A 0.72-mol sample of PCl₅ is put into a 1.00-L vessel and heated. At equilibrium, the vessel contains 0.40 mol of PCl₃(g) and 0.40 mol of Cl₂(g). Calculate the value of the equilibrium constant for the decomposition of PCl₅ to PCl₃ and Cl₂ at this temperature.
Step 1: Calculate the molar concentrations
[PCl₅]i = 0.72 mol/1.00 L = 0.72 M
[PCl₃]eq = 0.40 mol/1.00 L = 0.40 M
[Cl₂]eq = 0.40 mol/1.00 L = 0.40 M
Step 2: Make an ICE chart
PCl₅(g) ⇄ PCl₃(g) + Cl₂(g)
I 0.72 0 0
C -x +x +x
E 0.72-x x x
Step 3: Determine the value of x
Since [PCl₃]eq = [Cl₂]eq = 0.40 M, x = 0.40 M
Step 4: Determine the concentration of PCl₅ at equilibrium
[PCl₅]eq = 0.72-x = 0.72-0.40 = 0.32 M
Step 5: Calculate the equilibrium constant
Kc = [PCl₃] × [Cl₂] / [PCl₅]
Kc = 0.40 × 0.40 / 0.32 = 0.50