Answer:
b. chemical and physical
which statement about atoms is correct
A atoms contain protons and electrons in the nucleus
B Neutrons are negatively charged
c protons are positively charged
D the nucleon number is the number of neutrons
Answer:Protons are positively charged is the correct statement about an atom
I've also corrected the other statements
Atoms contain protons and neutrons in their nucleus
Neutrons posses no charge and are neutral
The nucleon number is the total number of protons and neutrons in a nucleus
Which is most often used to destroy bacteria?
15g of sugar and 10g of water are measured separately. The sugar is dissolved in the water. What will
the mass of the solution be?
Answer: a) No, both are different.
b) Ramesh- 9.9%
Sarika - 10%
Explanation:
According to the solution prepared by Ramesh,
Mass of sugar he took (Solute) = 10 g
Mass of water he took (Solvent) = 100 g
Thus Mass % of the solution =
According to the solution prepared by Sarika,
Mass of sugar she took (Solute) = 10 g
Mass of Solution she took = 100 g
Thus Mass % of the solution =
Explanation:
If 0.700 moles Ag is reacted with 10.0 g S, is sulfur or aluminum the limiting reactant?
Answer: [tex]S[/tex] is the limiting reagent
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} S=\frac{10.0g}{32g/mol}=0.3125moles[/tex]
[tex]\text{Moles of} Ag=0.700moles[/tex]
[tex]2Ag+S\rightarrow Ag_2S[/tex]
According to stoichiometry :
1 mole of [tex]S[/tex] require = 2 moles of [tex]Ag[/tex]
Thus 0.3125 moles of [tex]S[/tex] will require=[tex]\frac{2}{1}\times 0.3125=0.6250moles[/tex] of [tex]Ag[/tex]
Thus [tex]S[/tex] is the limiting reagent as it limits the formation of product and [tex]Ag[/tex] is the excess reagent.
During the combustion of methane (CH4), one mole of methane gas combines with two moles of oxygen gas (O2) to produce one mole of carbon dioxide gas (CO2) and two moles of water vapor. Which of the following chemical equations correctly represents the combustion of methane described above
Answer:
CH4(g) +2O2____ CO2(g) +2H2O (l)
Solid sodium reacts violently with water, producing heat, hydrogen gas, and sodium hydroxide. How many g of hydrogen gas are formed when 125.0 g of sodium are added to water?
2Na + 2H2O → 2NaOH + H2
Which best explains what happens to the carbon atoms in carbon dioxide during photosynthesis?
A They are incorporated into molecules of sugar.
B They are transformed into oxygen atoms.They are transformed into oxygen atoms.
C They are broken down into subatomic particles.They are broken down into subatomic particles.
D They are destroyed to release energy.They are destroyed to release energy.
c i think
Explanation:
if it's not look it up
HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP
prove you understand the development of democracy in Athens and how it influenced the government of the United States.
For this assignment, you will write two paragraphs:
In paragraph one, you will explain at least three ways that democracy in Athens influenced the United States government.
In paragraph two, you will explain at least three differences between Athenian and American democracy.
Answer:
The original U.S. voting system had some similarities with that of Athens. In Athens, every citizen could speak his mind and vote at a large assembly that met to create laws. Citizens were elected to special councils to serve as organizers, decision-makers, and judges. The Greek idea of democracy was different from present-day democracy because, in Athens, all adult citizens were required to take an active part in the government. ... This form of government is called direct democracy. The United States has a representative democracy.
Which of the following best describes the difference between metals and nonmetals?
a
metals tend to have low melting points and nonmetals have high melting points
b
nonmetals are more reactive than metals
c
metals are brittle and dull
d
metals have high melting points and are malleable, whereas, nonmetals have lower melting points and tend to be brittle.
Answer:
the answer is d.
Explanation:
because metals are refers to natural elements that are hard, shiney, opaque, and dense. nonmetals implies thise chemical substances that are soft, non-shiney, transparent and brittle.
Which statement are part of the safety protocol for this lab experiment?
Answer:
Always wear safety goggles when performing an experiment.
Use caution when constructing the track.
Ensure that the track is clear before releasing cars.
Report all accidents to the teacher.
Explanation:
In words, how does the volume change when the temperature of an object changes?
Facts about flooding
Answer:
No region is safe from flooding. All 50 states are subject to flash floods.[1]
Flash floods can bring walls of water from 10 to 20 feet high.[2]
A car can be taken away in as little as 2 feet of water.[3]
To stay safe during a flood, go to the highest ground of floor possible. If your skin comes in contact with flood water, make sure to wash it with soap and disinfected water because the contents are unknown.[4]
Flooding is caused by spring thawing (snow and frozen grounds melting in the spring), heavy rains, snow melt runoffs, flash floods, and mudflows.[5]
Floods are the most widespread natural disaster aside from wildfires. 90% of all U.S. natural disasters declared by the President involve some sort of flooding.[6]
In preparation for a flood, it is important to stock up on first aid items, non-perishable foods, 3 gallons of water per person for 3 days, battery operated radio for weather reports, extra batteries, personal hygiene necessities.[7]
Based on Floodsmart, a 2,000 square foot home undergoing 12” of water damage could cost more than $50,000.[8]
Since flood damage is almost never covered by homeowners insurance, flood insurance is important for people living in high-risk flood zones.[9]
To stay safe during a flood, go to the highest ground of floor possible. If your skin comes in contact with flood water, make sure to wash it with soap and disinfected water because the contents are unknown.[10]
Communities particularly at risk are those located in low-lying areas, near water, or downstream from a dam.[11]
A solution of 1.8274g of a polypeptide in 274mL of a aqueous solution has an osmotic pressure at 31.40 degrees C of 2.012 mmHg. The approximate molecular weight of this polymer is _____ g/mol.
Answer: Hence, the approximate molecular weight of the poymer is 64106 g/mol
Explanation:
[tex]\pi=CRT[/tex]
where,
[tex]\pi[/tex] = osmotic pressure of the solution = 2.012 mm Hg = 0.0026 atm
i = Van't hoff factor = 1 (for non-electrolytes)
Mass of solute (polypeptide) = 1.8274 g
Volume of solution = 274 mL
R = Gas constant = [tex]0.0821Latm/Kmol[/tex]
T = temperature of the solution = [tex]31.40^0C=(273+31.40)K=304.4K[/tex]
Putting values in above equation, we get:
[tex]0.0026=\frac{1.8274 g\times 1000}{M\times 274ml}\times 0.0821\times 304.4[/tex]
[tex]M=64106g/mol[/tex]
Hence, the approximate molecular weight of the poymer is 64106 g/mol
if water is added to a 0.70 molar solution of CuSO4 what will change
A. molarity will increase
B. Molarity will decrease
C. the amount of CuSO4 will decrease
D. No change in molarity or amount of salute
Answer:
B. Molarity will decrease
Explanation:
Molarity is one of the measures of the molar concentration of a solution. It is calculated by dividing the number of moles of the solute by the volume of the solvent. This means that the higher the amount of solute in relation to the volume of solvent, the higher the molarity of that solution.
In essence, adding water to a solution dilutes it i.e it increases the solvent's volume in relation to the solute, causing the molarity to decrease. In a nutshell, diluting a solution (by adding water or more solvent) causes the molarity of such solution to decrease. For example, if water is added to a 0.70 molar solution of CuSO4, the molarity of the solution will DECREASE.
D) 7
20 points
2. How does the concept of conservation of mass apply to chemical
reactions? (hint: the Law of Conservation of Mass) *
a) the reactants and products have exactly the same molecules
b) the change in the amount of matter is equal to the change in energy
o
c) the reactants and products have exactly the same atoms
d) the change in the amount of matter is only a small percentage of the total mass
W
3. How many Oxygen (O) atoms are in the chemical formula below?. *
Answer:
the reactants and products have have exactly the same molecules
The reactants and products have exactly the same atoms, therefore the concept of conservation of mass applies to chemical reactions. Therefore, option (b) is correct.
What is the law of conservation of matter?According to this law, matter can neither be created nor destroyed, but can be converted from one form to another. So the same number and type of atoms in a chemical reaction before and after the chemical change are present.
The initial substances or reactants change into different substances or products in any chemical change. Both the reactants and products are made up of atoms as all matter is made up of atoms.
The matter is conserved as the equal number of atoms of each element in the reactants and products, and the total mass of the reactants must equal the total mass of the products.
The law of conservation of mass can be only followed in a chemical reaction if the reactants and products have exactly the same atoms.
Learn more about the law of conservation of matter, here:
brainly.com/question/13383562
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Los termómetros de mercurio no pueden medir temperaturas menores a -30oC debido a que a esa temperatura el Hg
se hace pastoso. ¿Podrías indicar a qué temperatura Fahrenheit y Kelvin corresponde?
Answer:
243.15 K y -22 F
Explanation:
Para convertir la temperatura desde grados Celsius (°C) a kelvin (K) se debe sumar 273.15 K:
K = °C + 273.15 = -30°C + 273.15 K = 243.15 K
Para convertir desde grados Celsius (°C) a Fahrenheit (F), se multiplica por 9/5 y se suma 32, como sigue:
F = (9/5 x °C) + 32 = (9/5 x (-30°C)) + 32= -22 F
Por lo tanto, una temperatura de -30°C corresponde a 243.15 Kelvin y -22 grados Fahrenheit.
Characteristics of a substance that describe its' ability to change into a different substance are called?
I have 8 valence electrons, completely nonreactive, and my family contains Helium that is used to fill balloons! I must be a...
a
metal
b
nonmetal
c
metalloid
d
noble gas
Answer:
Noble gas
Explanation:
Noble gases are complete octets ( have 8 valence electrons) Helium is a member of this family.
How many moles of water are there in 45 g of water?
a) 1.0 moles
b) 1.5 moles
c) 2.0 moles
d) 2.5 moles
Answer:
d
Explanation:
can you help me with my question In the extended simile of the underlined passage from Paragraph 15 of "A Wagner Matinee," the narrator makes an observation about the soul that aring rokol been A. it is like a strange moss on a dusty shelf that, with excruciating suffering, can wither and die y for I the be B though after excruciating suffering it may seem to wither, the soul never dies, C. excruciating, interminable suffering that goes on for half a century can kill the soul.
Which statements correctly describe the human skeletal system?
O A. The skeletal system produces red blood cells.
B. Once made, bones become solid structures.
OC. Adult bones are made of non-living materials only.
D. There are many kinds of joints.
OE. Joints are bones that can bend.
Answer:
A
Explanation:
Well, the human skeletal system produce red blood cells into and for the body.
What is the energy of a photon of violet light with a frequency of 7.79*[tex]10^{14}[/tex] [tex]s^{-1}[/tex]? (answer in joules)
Answer:
[tex]E=5.16\times 10^{-19}\ J[/tex]
Explanation:
Given that,
The frequency of violet light, [tex]f=7.79\times 10^{14}\ Hz[/tex]
We need to find the energy of a photon. The formula for the energy of a photon is given by :
[tex]E=hf\\\\E=6.63\times 10^{-34}\times 7.79\times 10^{14}\\\\E=5.16\times 10^{-19}\ J[/tex]
So, the energy of a photon is equal to [tex]5.16\times 10^{-19}\ J[/tex].
SOMEONE HELP ME ASAP!!!
Answer:
A
Explanation:
Hey I'm Chloe can you Help me, Thank you :)
What pigment, only present in plants, makes photosynthesis possible?
Answer:
la photosintesis viene de la clorofila de la planta
Why are most anions basic in H2O? Give formulas of four anions that are not basic.
Answer:
The anions that can act as bases (conjugate bases of weak acids) have the capability to hydrolyse water and produce OH− ions. Cl−, Br−NO−3, SO2−4 are all conjugate bases of strong acids that don't have the capability to hydrolyse water and so they aren't basic.
Explanation:
The gravitational force between two masses is proportional to
A.
the difference between the masses.
B.
the first mass divided by the second mass.
C.
the product of the masses.
D.
the sum of the masses.
Answer:
D.
the sum of the masses.
Explanation:
Help please for this problem.
Question number 12 I need help
Answer: Its B.
Explanation:
i cant quite explain
how many grams of Al(no2)3 should be added to 1.3L of water to prepare a 2.0M solution
Answer: 429 grams of [tex]Al(NO_2)_3[/tex] should be added to 1.3 L of water to prepare 2.0 M solution
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute [tex]Al(NO_2)_3[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{xg}{165g/mol}[/tex]
[tex]V_s[/tex] = volume of solution in Liters
Now put all the given values in the formula of molarity, we get
[tex]2.0M=\frac{xg}{165g/mol\times 1.3L}[/tex]
[tex]x=429g[/tex]
Therefore, 429 grams of [tex]Al(NO_2)_3[/tex] should be added to 1.3 L of water to prepare 2.0 M solution
What is the definition of an Arrhenius acid?
Answer:
B. An Arrhenius acid increases [OH–] in the Solution
Answer:
An Arrhenius acid increases [H+] in the solution.
Explanation:
i just took the test and this was the answer-
What is this what is this
Answer:Attemted Failed
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