Answer:
The bones of the skull and spinal column
Explanation:
The central nervous system is better protected than any other system or organ in the body. Its main line of defense is the bones of the skull and spinal column, which create a hard physical barrier to injury.
Answer:
The Central Nervous System (CNS)
Hydrogen has an oxidation number of +1 in all compounds excepts when it binds with metals and has an oxidation state of -1.
Answer:
See explanation
Explanation:
In the periodic table, hydrogen is placed in group 1 for convenience. Hydrogen is not a metal, however, its common oxidation state is +1. It easily forms a univalent positive ion just like group 1 elements.
So, when hydrogen is combined with strongly electropositive metals such as sodium, lithium, etc, hydrogen accepts one electron and exhibits an oxidation state of -1 in those compounds.
Such compounds in which hydrogen is combined with strongly electropositive metals to give a binary compound is called a hydride.
Which of these elements has the lowest ionization energy?
A. Si
B. CI
C. S
D. Na
Answer:
D . Na
Explanation:
At what minimum temperature do rocks melt into lava?
A) 3,500 degrees Celsius
B) 6,332 degrees Fahrenheit
C) 800 degrees Fahrenheit
OD 800 degrees Celsius
Rocks are classified as sedimentary, metamorphic, or igneous on the basis of
the
a. age of the rocks.
b. way the rocks were formed.
c. types of fossils the rocks contain.
d. number of minerals found in the rocks.
HELP ME
Elements in a vertical column on the Periodic Table have similar properties and are all members of the same
of elements.
А
molecule
B
phase
С
atom
D
group
Answer:
D group
................
what is a 7 letter word that starts with f: Ancient plants and animals formed into rocks.
Answer:
Fossils?
Explanation:
The human body can get energy by metabolizing proteins, carbohydrates or fatty acids, depending on the circumstances. Roughly speaking, the energy it gets comes mostly from allowing all the carbon atoms in the food molecules to become oxidized to carbon dioxide CO2 by reaction with oxygen from the atmosphere. Hence the energy content of food is roughly proportional to the carbon content.
Let's consider alanine, C3H7NO2, one of the amino acids from which proteins are made, and glucose C6H12O6, one of the simplest carbohydrates. Using the idea above about energy content, calculate the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose.
Answer:
the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose is 1.0111
Explanation:
Given the data in the question;
To determine the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose, first we get the molar masses of both alanine and glucose
we know that;
Molar mass of alanine ( C₃H₇NO₂ ) = 89.09 g/mol
Molar mass of glucose ( C₆H₁₂O₆ ) = 180.16 g/mol
now, { metabolizing each gram }
moles of alanine = mass taken / molar mass
= 1g / 89.09 g/mol = 1/89.09 moles
moles of glucose = mass taken / molar mass
= 1g / 180.16 g/mol = 1/180.16 moles
In each molecule of alanine, we have 3 atoms of carbon.
Also, in each molecules of glucose, we have 6 atoms of carbon
so,
number of moles of Carbons in alanine = 3 × 1/89.09 moles = 0.03367
number of moles of Carbons in glucose = 6 × 1/180.16 moles = 0.0333
so ratio of energy will be the ratio of carbon atoms, which is;
⇒ 0.03367 / 0.0333 = 1.0111
Therefore, the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose is 1.0111
Copper has a specific heat of 0,900 J(g C). How much energy in kJ is needed to raise the temperature of a 700 g block of aluminum from 30.7°C to 82,1C?(show your steps)
Answer:
32.4 kJ
Explanation:
Given that:
Specific heat capacity fo copper, c = 0.9
Mass of copper, m = 700 g
Temperature change, dθ ;t2 - t1 = (82.1 - 30.7) = 51.4
Energy required, E = mcdθ
E = 700 * 0.9 * 51.4
E = 32382 J
Energy required on kJ
32382 / 1000
= 32.382 kJ
= 32.4 kJ
hi, if your looking for extra points (50+) and br ainiest here is ur chance, answer this question correctly plz
number of molecules in lithium sulfate Li2So4
how many moles of nitrogen gas are produced in the reaction if we started with 6 moles of ammonium nitrate
oil has a density of 8.5kg/L. what is the volume of 5.4kg oil
Answer:
0.64 L
Explanation:
Step 1: Given data
Density of oil (ρ): 8.5 kg/LMass of oil (m): 5.4 kgVolume of oil (V): ?Step 2: Calculate the volume corresponding to 5.4 kg of oil
Density is an intrinsic property and it is equal to the quotient between the mass and the volume.
ρ = m/V
V = m/ρ
V = 5.4 kg/(8.5 kg/L) = 0.64 L
Calculate the pH of each of the following aqueous solutions. (Enter your answers to two decimal places.) (a) 10.0 mL deionized water WebAssign will check your answer for the correct number of significant figures. 2.72 Incorrect: Your answer is incorrect. (b) 10.0 mL deionized water plus 5.0 mL of 0.10 M NaOH WebAssign will check your answer for the correct number of significant figures. (c) 10.0 mL deionized water plus 10.0 mL of 0.10 M NaOH WebAssign will check your answer for the correct number of significant figures. (d) 10.0 mL deionized water plus 15.0 mL of 0.10 M NaOH WebAssign will check your answer for the correct number of significant figures.
Answer:
a. pH = 7.0
b. pH = 12.52
c. pH = 12.70
d. pH = 12.78
Explanation:
a. Deionized water has the [H⁺] of pure water = 1x10⁻⁷ (Kw = 1x10⁻¹⁴ = [H⁺][OH⁻] - [H⁺] = [OH⁻ -)
pH = -log[H⁺] = 7
b. Moles NaOH = 5x10⁻³L * (0.10mol / L) = 5x10⁻⁴moles OH⁻ / 0.015L = 0.0333M = [OH⁻]
-Total volume = 10mL+5mL = 15mL = 0.015L
pOH = -log[OH⁻] = 1.48
pH = 14-pOH
pH = 12.52
c. Moles NaOH = 0.010L * (0.10mol / L) = 1x10⁻³moles OH⁻ / 0.020L = 0.0500M = [OH⁻]
-Total volume = 10mL+10mL = 20mL = 0.020L
pOH = -log[OH⁻] = 1.30
pH = 14-pOH
pH = 12.70
d. Moles NaOH = 0.015L * (0.10mol / L) = 1.5x10⁻³moles OH⁻ / 0.025L = 0.060M = [OH⁻]
-Total volume = 10mL+15mL = 25mL = 0.025L
pOH = -log[OH⁻] = 1.22
pH = 14-pOH
pH = 12.78
Which obstacle was faced by African Americans serving in the armed forces during World War II?
They were forced to serve in segregated units.
They were not subject to military conscription.
ОООО
None of them ever saw combat during the war.
They were placed under French command.
Help help help !!!!!!
Answer:
3. 116.5 V
4. 119.6 V
Explanation:
3. Determination of the voltage.
Resistance (R) = 25 Ω
Current (I) = 4.66 A
Voltage (V) =?
V = IR
V = 4.66 × 25
V = 116.5 V
Thus, the voltage is 116.5 V
4. Determination of the voltage.
Current (I) = 9.80 A
Resistance (R) = 12.2 Ω
Voltage (V) =?
V = IR
V = 9.80 × 12.2
V = 119.6 V
Thus, the voltage is 119.6 V
What is the correct shape and polarity of a water molecule
Answer:
D
Explanation:
because both H's should be positive and O is supposed to be negative.
Whoever gets these 2 right gets brainliest! :)
the first one is A covalent bond.
the second one is Answer: B Decomposition
How many atoms are in 90.43 moles of copper
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.12×10²³ atoms are in 90.43 mole of copper.
What is mole?
The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.
we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number
number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)
number of moles of copper=90.43 moles
Substituting all the given values in the above equation, we get
number of atoms/molecules= 90.43 × 6.022×10²³
number of atoms/molecules=8.12×10²³ molecules
Therefore, 8.12×10²³ atoms are in 90.43 mole of copper.
To know more about mole, here:
https://brainly.com/question/15209553
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A student plans a two-step synthesis of 1-ethyl-3-nitrobenzene from benzene. The first step is nitration of benzene to give nitrobenzene, and the second step is a Friedel-Crafts alkylation using CH3CH2Cl and AlCl3. The plan is flawed because: A : When the alkyl halide interacts with AlCl3, the resulting carbocation can rearrange before it has a chance to react with the aromatic ring. B : Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation. C : The nitro group will direct the incoming alkyl group para position, rather than to the meta position. D : A blocking group is required to achieve this synthesis.
Answer:
Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.
Explanation:
The benzene ring in itself does not easily undergo electrophilic substitution reaction. Some groups activate or deactivate the benzene ring towards electrophilic substitution reactions.
-NO2 ia a highly deactivating substituent therefore, Friedel-Crafts alkylation of nitrobenzene does not take place under any conditions.
This reaction scheme is therefore flawed because Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.
What enzyme catalyses the reaction of PRPP transfer to hypoxanthine with
formation of IMP?
Answer:
HPRT
Explanation:
HPRT catalyzes the salvage reactions of hypoxanthine and guanine with PRPP to form IMP and GMP
The formation of GMP from IMP requires oxidation at C-2 of the purine ring, followed by a glutamine-dependent amidotransferase reaction that replaces the oxygen on C-2 with an amino group to yield 2-amino,6-oxy purine nucleoside monophosphate, or as this compound is commonly known, guanosine monophosphate.
How many grams equal 4.3 x 1024 atoms of oxygen (02)?
Answer: 248.66g
Explanation:
4.3e24 / 6.23e23 = 6.9 mols O2
6.9(18.02*2)=248.66
PLEASE HELP IMMEDIATE WORTH 10 POINTS
Fill in the blank with the word or phrase that best completes the statement or answers the question. The scientific name for a plant that reproduces with flowers is a(n)
Answer:
the scientific name is Angiosperms
Explanation:
please mark brainliest
A certain protein transports a sodium ion from the inside of the cell membrane to the outside using active transport. Which of the following must be true? A. There is no change in concentration before or after transport. B. The transport process did not use chemical energy. C. After transport, the concentration of protein in the cell decreases. D. After transport, the concentration of sodium is lower inside the cell.
Suppose an EPA chemist tests a 250.mL sample of groundwater known to be contaminated with nickel(II) chloride, which would react with silver nitrate solution like this: NiCl2(aq) + 2AgNO3(aq) → 2AgCl(s) + NiNO32(aq) The chemist adds 15.0mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 5.8mg of silver chloride. Calculate the concentration of nickel(II) chloride contaminant in the original groundwater sample. Round your answer to 2 significant digits.
Answer:
0.0010 w/v %
Explanation:
Based on the reaction:
NiCl₂(aq) + 2AgNO₃(aq) → 2AgCl(s) + Ni(NO₃)₂(aq)
Finding the moles of AgCl produced we can find the moles of NiCl in the reaction medium and its mass:
Moles AgCl -Molar mass: 143.32g/mol-:
5.8mg = 5.8x10⁻³g * (1mol / 143.32g) = 4.047x10⁻⁵ moles AgCl
Moles NiCl₂:
4.047x10⁻⁵ moles AgCl * (1mol NiCl₂ / 2mol AgCl) = 2.023x10⁻⁵ moles NiCl₂
Mass NiCl₂ -Molar mass: 129.60g/mol-:
2.023x10⁻⁵ moles NiCl₂ * (129.60g / mol) = 2.62x10⁻³g of NiCl₂ are produced.
And the concentration in w/v% is:
2.62x10⁻³g NiCl₂ / 250mL * 100 =
0.0010 w/v %What is produced when concentrated aqueous sodium chloride is electrolysed?
CAN SOMEONE PLEASE HELP ME I WILL MARK AS BRAINLIEST :(
Answer:
ok so i did the problem and the answer was 8e+29
Explanation:
i dont really know what the answer is but thats the answer i got
sorry if this didnt help
If you began a reaction with the following ions in solution, what would be the net ionic equation?
Na+, PO43–, Fe2+, and NO3–
Answer:
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
Explanation:
Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).
Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)
The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
Lithium and nitrogen react to produce lithium nitride:
6Li (s) + N2 (g) = 2Li3N (s)
How many moles of lithium nitride are produced when 0.400 mol lithium are used in this reaction?
a. 1.28 mol
b. 0.133 mol
c. 0.800 mol
d. 0.0667 mol
Answer:
B : 0.133 M
Explanation:
moles Li3N3 = 0.4 mol Li x (2 moles Li3N/6 moles Li) = 0.133 M
Do you think humans are responsible for global warming trends? Why or why not?
Answer:
Yes. At least some. There has been ups and downs in temperature ever since the Earth was created, and this is just another up in temperature. I do think that humans have made it worse though, with all of the greenhouse gases and things like that.
______ occur between molecules that have permanent intramolecular differences in elecronegativity.
A. Dipole-dipole interactions
B. Dispersion forces
C. Hydrogen bonds
Answer:
Dipole-dipole interactions
Explanation: