ANSWER ASAP
2. The figure shows the first three rows, or periods, of the periodic table. Suppose the fourth period is added. How many orbits will the Bohr models in the fourth period have? How many electrons will an atom in Group 1 in the fourth period have?
Answer:
4 orbits in the fourth period.
19 electrons in the atom from group 1 and fourth period.
Explanation:
Potassium has 19 electrons distributed in its 4 orbits
The number of periods in a periodic table, tells the number of shells or orbitals of the atoms in that row in which the electrons are filled. Thus the fourth period elements have 4 orbitals and the first element in group one of the fourth period is potassium containing 19 electrons.
What are periods in periodic table?All elements in a periodic table are classified into different groups and periods. The vertical columns in the periodic table is called groups and the horizontal rows are called periods.
A group contains elements with same number of valence electrons and similar physical and chemical properties. In a period from left to right the atomic number increases but the number of orbitals in which the electrons are filled will be the same.
Down a group the number of orbitals increases by one. Thus, each elements contains electrons in an increment of 8, 18, 18 and 32 down a group. Thus, from third period to fourth period the number of orbital increases to 4.
The number of electrons will be +8 from the previous element in the group in third period. Thus, below sodium (11) the first element in fourth period is potassium with 19 electrons.
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In the 1860's the Central Pacific Railroad company employed the chemist James Howden to make an explosive capable of blasting through the granite mountains of the Sierras. The railroad needed tunnels for their train to pass through. James Howden built a nitroglycerin producing lab on Donner Pass where he would make the explosive compound on command. Nitroglycerin has the chemical formula C3H5N3O9. When it is detonated, it decomposes into carbon dioxide, water, oxygen and nitrogen. What is the theoretical yield for moles of nitrogen gas produced upon detonation of 1.320 tons of nitroglycerin? There are 907185 grams in 1 ton and nitroglycerin has a molar mass of 227 g/mol. Do not include decimals in your answer.
Answer:
8 × 10³ mol N₂
Explanation:
Step 1: Write the balanced equation
2 C₃H₅N₃O₉ ⇒ 6 CO₂ + 5 H₂O + 0.5 O₂ + 3 N₂
Step 2: Convert the mass of C₃H₅N₃O₉ from tons to grams
We will use the conversion factor 1 t = 907185 g.
1.320 t × 907185 g/1 t = 1.197 × 10⁶ g
Step 3: Calculate the moles corresponding to 1.197 × 10⁶ g of C₃H₅N₃O₉
The molar mass of C₃H₅N₃O₉ is 227 g/mol.
1.197 × 10⁶ g × 1 mol/227 g = 5.27 × 10³ mol
Step 4: Calculate the moles of N₂ formed from 5.27 × 10³ moles of C₃H₅N₃O₉
The molar ratio of C₃H₅N₃O₉ to N₂ is 2:3.
5.27 × 10³ mol C₃H₅N₃O₉ × 3 mol N₂/2 mol C₃H₅N₃O₉ = 7.91 × 10³ mol N₂ ≈ 8 × 10³ mol N₂
which changes when gases condense to form liquids
In condensation, matter changes from a gas to a liquid. All matter is made of tiny moving particles called molecules. Evaporation and condensation happen when these molecules gain or lose energy. This energy exists in the form of heat.
DAE
On the first day of school, a class of fifth-grade students are given four identical cubos of hard clay. The cubes are placed in four different conditions until the last day of school. At that time, the students make the following
observations
Sample 1: classroom cabinetno noticeable changes
Sample 2 near a window lighter in color
Sample 3: freezer - small cracks near comers
Sample 4 bottle of water small amount of algae on top Which sample shows evidence of physical weathering?
Sample 1
Sample 2
оооо
C
Samples
Sample 4
Answer:
sample 3
Explanation:
i did this
Answer:
Sample 3
Explanation:
physical weathering means the breaking down of an object physically and the small cracks represent physical change.
Please Help! (Chemistry Molecules to Grams)
Answer:
20.95 g of caffeine, C₈H₁₀N₄O₂
Explanation:
From the question given above, the following data were obtained:
Number of molecules of C₈H₁₀N₄O₂ = 6.5×10²² molecules
Mass of C₈H₁₀N₄O₂ =?
From Avogadro's hypothesis,
1 mole of C₈H₁₀N₄O₂ = 6.02×10²³ molecules
Next, we shall determine the mass of 1 mole of C₈H₁₀N₄O₂. This can be obtained as follow:
1 mole of C₈H₁₀N₄O₂ = (8×12) + (10×1) + (4×14) + (2×16)
= 96 + 10 + 56 + 32
1 mole of C₈H₁₀N₄O₂ = 194 g
Thus,
194 g of C₈H₁₀N₄O₂ = 6.02×10²³ molecules
Finally, we shall determine the mass of caffeine, C₈H₁₀N₄O₂ that contains 6.5×10²² molecules. This can be obtained as follow:
6.02×10²³ molecules = 194 g of C₈H₁₀N₄O₂
Therefore,
6.5×10²² molecules = (6.5×10²² × 194) / 6.02×10²³
6.5×10²² molecules = 20.95 g of C₈H₁₀N₄O₂.
Therefore, 20.95 g of caffeine, C₈H₁₀N₄O₂ contains 6.5×10²² molecules
Identify the components of the ionic formula based on the name strontium phosphide. What is the symbol for the element that forms the positive cation? What is the symbol for the element that forms the negative anion? What is the subscript on the cation in the neutral formula? What is the subscript on the anion in the neutral formula?
Answer: The components are Strontium (Sr) and Phosphorous (P). The symbol for the element that forms the positive cation is [tex]Sr^{2+}[/tex]. The symbol for the element that forms the negative anion is [tex]P^{3-}[/tex]. The subscript on the cation in the neutral formula is 3 and the subscript on the anion in the neutral formula is 2.
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here in strontium phosphide , element strontium is having an oxidation state of +2 called as [tex]Sr^{2+}[/tex] cation and element phosphorous [tex]P^{3-}[/tex] is an anion with oxidation state of -3. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral strontium phosphide [tex]Sr_3P_2[/tex]
What important function do currents and areas of upwelling provide for living things
in the sea?
Recycles the ocean water through evaporation and precipitation
Brings nutrients up from deeper water for use by organisms
Mixes land and sea organisms to broaden the food web
Allows Earth to have weather and climate changes
Please help asap!!
A cooling curve has two flat lines, or plateaus. What does the plateau at the higher temperature represent?
Select one:
a. Increase in temperature of a liquid
b. Decrease in temperature of a gas
c. Condensation of a gas
d. Freezing of a liquid
A cooling curve has two flat lines, or plateaus. The plateau at the higher temperature represents condensation of a gas and the correct option is option C.
What is Cooling curve?
When a solid substance is heated until it is completely melted, and then heated further and allowed to cool slowly, the curve obtained by plotting temperature against time is known as the cooling curve.
The gradient of the cooling curve is related to the heat capacity, the thermal conductivity of the substance, and the external temperature. The more heat is required to change the temperature of the substance, the slower it cools, so the smaller the gradient of the curve. The higher the thermal conductivity, the faster heat is transferred, so the faster the substance cools.
Therefore, A cooling curve has two flat lines, or plateaus. The plateau at the higher temperature represents condensation of a gas and the correct option is option C.
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What do cuticles do for land plants that was not necessary for ancestors that lived in water
A. Cuticles Allow them to grow bigger and Taller.
B. Cuticles help them transport water.
C. Cuticles help prevent water loss.
D. Cuticles allow the performance of photosynthesis.
Which energy resource causes the greatest waste disposal concerns?
solar power
nuclear
coal
geothermal power
what kind of crystalline solid is graphite?
Answer:
Covalent-network (also called atomic) solids—Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes.
I hope it's helpful!
Answer:
network solid
Explanation:
What is the name of the process happening in the picture? How do you know it’s that process? Explain your answer in 2 to 3 complete sentences
alquien por favor que me ayude con ejercicios de química orgánica?
dime cómo es el trabajo y veo si te puedo ayudar
ou are a work study for the chemistry department. Your supervisor has just asked you to prepare 500 mL of 3 M HCl for tomorrow’s undergraduate experiment. In the stockroom explorer, you will find a cabinet called "stock solutions". Open this cabinet to find a 2.5 L bottled labeled "11.6 M HCl". The concentration of the HCl is 11.6 M. Please prepare a flask
Answer:
Add to a 500mL volumetric flask 300mL of water, the 129mL of the 11.6M HCl solution and then complete to volume with water
Explanation:
To make 500mL = 0.500L of a 3M HCl from the 11.6M HCl stock we need first to find the moles of HCl we need:
Moles HCl:
0.500L * (3mol / L) = 1.5 moles of HCl are needed
These moles are obtained from the 11.6M HCl solution. The volume required is:
1.5mol * (1L / 11.6moles HCl) = 0.129L = 129mL must be added to the solution.
That means to prepare the 500mL of the 3M HCl you need to:
Add to a 500mL volumetric flask 300mL of water, the 129mL of the 11.6M HCl solution and then complete to volume with water
Answer:
Calculation: 11.6 M × V = 3.0 M × 0.500 liters
V = 0.13 liters
Steps for dilution:
Measure out 0.13 liters of the concentrated solution of 11.6 M HCl using a volumetric pipet.
Transfer this into solution into a 500 milliliter volumetric flask.
Add water to the flask until it reaches a total volume of 500 milliliters.
Solution: V = 0.13 liters
Explanation:
Which of these describes the essential conclusion of the Rutherford experiment? The atom contains a very small nucleus that contains most of its mass. The proton is positively charged and the neutron has no charge? Atoms are solid spheres with electrons suspended in them like chocolate chips in a cookie. Mass is neither made nor consumed in a chemical reaction.
Answer:
The atom contains a vey small small nucleus that contains most of its mass.
Explanation:
The Rutherford gold leaf experiment concluded that most (99%) of all the mass of an atom is in the nucleus of the atom, that the nucleus is very small (105 times small than the size of the atom) and that is is positively charged.
A kerosene stove that produces 0.8 g/hr of carbon monoxide (CO) is used in a closed room with a volume of 200 m3. Fresh air enters the room at the rate of 40 m3/hr and stale air leaves at the same rate. Assuming complete mixing and that carbon monoxide is a conservative pollutant (i.e., does not undergo decay), determine the steady state CO concentration
Answer:
20 mg/m3
Explanation:
Given -
S = 0.8 g/hr
Q = 40m3/hr
V =200 m3
As we know, the steady state CO concentration is given by
Css = S/Q
= 0.8/(40m3/hr)
= 800 mg/hr/(40m3/hr)
= 20mg/m3
Predict whether each of the following ionic compounds is soluble in water: a.) LiCl d.) K2 ____________________ ____________________ b.) AgCl c.) BaCO3 ____________________ e.) Fe(NO3 ____________________ )3 ____________________ O
Answer:
See answer below
Explanation:
a.) Lithium Chloride, LiCl is soluble in water.
b.) Silver Chloride, AgCl is insoluble in water.
c.) Barium Carbonate, BaCO3 is insoluble in water.
d.)Potassium, K2 is soluble in water.
e.) Iron (III) Nitrate Fe(NO3)3 is soluble in water.
All nitrates (NO3) are soluble in water.Alkali metals are soluble in water.Chlorides are soluble in water with the exception of AgCl and a few others.Carbonates are generally insoluble in water.What happens to matter that is used up during photosynthesis?
It retains its form and mass.
It retains its form but increases in mass.
It changes to a new form of matter with less mass.
It changes to a new form of matter with the same mass.
Answer:
I am almost positive that it is D. I might be incorrect do i appoligise if i am.
Explanation:
The work of which scientist was most essential to the use of radioactive
isotopes in medicine?
A. Antoine-Laurent Lavoisier
B. Robert Boyle
C. Marie Curie
D. John Dalton
Answer:
A
Antoine-Laurent Lavoisier
:D
The scientist was most essential to the use of radioactive isotopes in medicine is " John Lawrence's".
What is radioactive isotopes?The radioactive isotopes of such an element were called radioisotopes. Atoms that have too much energy in their nucleus or even an unstable neutron-proton pair.
It marked the beginning of John Lawrence's lengthy career of service and the first time a radioactive isotope had already been employed in the management of a human illness. His laboratory is regarded as the origin of nuclear medicine, for which he is regarded as its father.
The scientist most essential to the use of radioactive isotopes in medicine is " John Lawrence's".
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A species is
O the least specific group
O not a group at all
o the most specific group
the largest group
11. Why is HCl a strong acid and HClO a weak acid?
14. Which of the following statements about phase changes are TRUE?
Answer:
Hate to take up this answer spot, but there is no statements about phase changes.
Here are some phase changes to help: when matter changes phase. Most common ex. is water(liquid) to ice(solid). It is created by particles coming together, or spreading apart.
Brainliest?
Pls help me I’m having a hard day pls answer these?
Answer:the first one is D second one is A and the third one is A :D
Explanation:
Geosmin is an aroma compound found in raindrops. It's chemical formula is C12H22O. The molar mass is 182 g/mol. If you perform combustion analysis of 1.77 grams of this compound, how many grams of carbon should be isolated as CO2 during the analysis?
Answer:
5.13 g of CO₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
C₁₂H₂₂O + 17O₂ —> 12CO₂ + 11H₂O
Next, we shall determine the mass of C₁₂H₂₂O that reacted and the mass of CO₂ produced from the balanced equation. This can be obtained as follow:
Molar mass of C₁₂H₂₂O = 182 g/mol.
Mass of C₁₂H₂₂O from the balanced equation = 1 × 182 = 182 g
Molar mass of CO₂ = 12 + (2×16)
= 12 + 32
= 44 g/mol
Mass of CO₂ from the balanced equation = 12 × 44 = 528 g
SUMMARY:
From the balanced equation above,
182 g of C₁₂H₂₂O reacted to produce 528 g of CO₂.
Finally, we shall determine the mass of CO₂ produced from the reaction. This can be obtained as follow:
From the balanced equation above,
182 g of C₁₂H₂₂O reacted to produce 528 g of CO₂.
Therefore, 1.77 g of C₁₂H₂₂O will react to produce = (1.77 × 528)/182 = 5.13 g of CO₂.
Thus, 5.13 g of CO₂ were obtained from the reaction.
ecology is the study of what
Answer:
Relative organisms
Explanation:
Ecology is a branch of biology that deals with the relations of organisms to one another and to their physical surroundings and conditions.
hope this helps:)
Here’s the answers I wasn’t asking a question hehe!Subtract the mass of the filter paper (0.27g) from the mass of the paper and copper (0.98 g). Record the difference in the data table as the amount of copper.
You already converted mass to moles for the reactants. Now convert mass to moles for the product, copper
all for edge
ANSWERS!!!
Which type of lens would you use in a microscope or telescope and why?
Answer:
Microscopes and telescopes often use two lenses to make an image large enough to see. A compound microscope uses two lenses to achieve high magnification. Both lenses are convex, or converging. Light from the object first passes through the objective lens.
Explanation:
A compound microscope uses two lenses to achieve high magnification
There is a third bromobutene structure that could have been formed in the addition of HBr to butadiene: cis-1-bromor-2-butene (the cis isomer of structure 2). Draw this structure. Would you predict (no calculation) its heat of formation to be more or less negative that the trans isomer? Explain.
Answer:
its less negative hope I helped buster
Because trans isomers are more stable than cis isomers, the cis isomer will have a less negative heat of formation than the trans isomer.
What are cis- and trans- isomers?Cis- and trans isomers are compounds that have different configurations in space because of the presence of a rigid structure or functional groups in their molecule.
Cis atoms have functional groups on the same side.
Trans isomers have functional groups on alternate different.
The structure of cis-1-bromor-2-butene is attached.
Generally, trans isomers are more stable than cis isomers..
Stable compounds have more negative heat of formation while unstable compounds have less negative heat of formation.
Therefore, the cis isomer will have a less negative heat of formation than the trans isomer.
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A student wants to know if the weight of a cart affects its speed at the bottom of a ramp. He can change the weight of the cart by adding different numbers of balls, and he can change the height of the ramp by using different numbers of blocks. Which set of tests should he compare? MARKING BRAINLIEST
Answer:d
Explanation:
Write the molecular equation for the reaction that occurs, if any, when solutions of the following substances are mixed: nitric acid and potassium carbonate. Make sure that you have properly identified all of the phases in your answer.
Answer:
The balanced molecular equation for the reaction is:
[tex]2HNO_{3_{(aq)} }[/tex] + [tex]K_{2} CO_{3} _{(s)}[/tex] → [tex]2KNO_{3} _{(s)}[/tex] + [tex]H_{2} O_{(l)[/tex] + [tex]CO_{2} _{(g)}[/tex]↑
Explanation:
The weak nitric acid reacts with the strong potassium base to produce salt, water and carbon dioxide which is given off.
Molecular ratio of reactants is 2 : 1.
All phases are represented in the equation: aq for aqueous, l for liquid and g for gas (notice how they are written in subscript).
I hope this was helpful.
