Answer:
It's considered a limited resource because there is a limited amount of freshwater found on Earth's surface. Explain why the amount of water per person differs between countries. It differs because in the different countries it is distributed unevenly.
Explanation:
looked it up
Caffeine has the molecular formula, C8H10N4O2. What is the percent composition of caffeine?
Select one:
a) 33.33% C, 41.67% H, 16.67% N, and 8.33% O
b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O
c) 25% C, 25% H, 25% N, 25% N, and 25% O
d) 27.92% C, 2.34% H, 32.56% N, and 37.19% O
Answer:
b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O
Explanation:
we find the mass for each element in one mole by multiplying the number of atoms in one molecule with the atomic mass
mC=8Ac=8*12=96g
mH=10AH=10*1=10g
mN=4AN=4*14=56g
mO=2AO=2*16=32g
by adding the masses together we find the molar mass of the molecule
M=mC+nH+mN+mO=96+10+56+32=194g/mole
we apply the rule of threes to find the percentage of each element
194g..96gC..10gH...56gN....32gO
100g....a...........b...........c.............d
a=(100*96)/194=49.48%C
b=(100*10)/194=5.19%H
c=(100*56)/194=28.85%N
d=(100*32)/194=16.48%O
what is the total number of atoms in a molecule of the compound li2so4
Answer:
Explanation:
Element Symbol Atomic Mass # of Atoms Mass Percent
Lithium Li 6.941 2 12.626%
Oxygen O 15.9994 4 58.209%
Sulfur S 32.065 1 29.165%
Why can’t a smartphone disappear completely in liquid acid?
Answer:
its metal because its metal
Which neutral element could be represented by the Electron Dot Structure below?
Answer:
oxygen as it has 6 valence electrons
When the bromine atom becomes an anion, it ______ in size.
Group of answer choices
A. increase
B. decrease
C. remains the same
When the strontium atom becomes a cation, it ______ in size.
A. increase
B. decrease
C. remains the same
Explanation:
Anions and cations have different atomic sizes than the neutral atoms.
When the bromine atom becomes an anion, it ______ in size.
Anions involves gaining extra electrons. This basically leads to increased repulsion between the electrons and thereby increasing the size. Anions are always larger than the neutral atoms.
This means the answer is A. Increase
When the strontium atom becomes a cation, it ______ in size.
Cations involves losing valence electrons. This basically leads to a decrease in electron shells and electron repulsion thereby reducing the size. Cations are always larger than the neutral atoms.
This means the answer is B. Decrease
bohr's work demonstrate the importance of communication in science because it wouldn't have been possible without the work of other scientists.
true or false
Answer:
Why science communication is important? In the world we live in, not only does pursuing science matter but communicating about it effectively is important as well. Communicating about science is crucial, whether we communicate about it online or face to face, communication about the scientific facts is vital for the scientific community. This is especially important now when many question scientific methods, research, and results. We are not only talking about communication about science between academics, scientists and corporations, but we are also talking about the gap between the scientific world and non-scientific community.
true
The given statement is true.
• The atomic model of Bohr was based on the model given by Rutherford as he clarified the location of electrons.
• Based on Bohr's model, the electrons only at the fixed distances from the nucleus orbit around it known as the energy levels.
• The work of Bohr illustrates the significance of communication in science as it would not be possible without the contribution of other scientists.
• The atomic model of Bohr was built upon the atomic models of other scientists, mainly Rutherford.
Thus, the given statement is true.
To know more about:
https://brainly.com/question/1862481
Which parts of the atom move around the nucleus? (Plz help)
Answer: Electrons
Explanation: The electrons are found outside the nucleus and orbit it.
What is the force of gravity between the earth and the mass of 1kg placed on its surface? (Mass of earth = 6 x 10^24 kg)
Given that,
Mass, m = 1 kg
Mass of the Earth, [tex]M=6\times 10^{24}\ kg[/tex]
Radius of Earth, r = 6378 km
To find,
The gravitational force.
Solution,
The formula for the gravitational force is given by :
[tex]F=\dfrac{GmM}{r^2}\\\\F=\dfrac{6.67\times 10^{-11}\times 1\times 6\times 10^{24}}{(6378 \times 10^3)^2}\\\\F=9.83\ N[/tex]
So, the required force is 9.83 N.
A gas has a volume of 13.4 L at 17C. What is the volume of the gas at standard temperature?
Answer:
This law states that the volume and temperature of a gas have a direct relationship: As temperature increases, volume increases, when pressure is held constant. Heating a gas increases the kinetic energy of the particles, causing the gas to expand.
Explanation:
Considering the Charles's law and STP conditions, the volume of the gas at standard temperature is 12.61 L.
Charles's lawCharles's law establishes the relationship between the volume and temperature of a gas sample at constant pressure.
This law says that for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases. That is, the volume is directly proportional to the temperature of the gas.
Mathematically, Charles's law states that the ratio between volume and temperature will always have the same value:
[tex]\frac{V}{T} =k[/tex]
Considering an initial state 1 and a final state 2, it is fulfilled:
[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]
Definition of STP conditionThe STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C (or 273 K) are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Volume of the gas at standard temperatureIn this case, you know:
V1= 13.4 LT1= 17 C= 290 K (being 0 C= 273 K)V2= ?T2= 0 C= 273 K (at STP)Replacing in the definition of Charles's law:
[tex]\frac{13.4 L}{290 K} =\frac{V2}{273 K}[/tex]
Solving:
[tex]V2= 273 K\frac{13.4 L}{290 K}[/tex]
V2= 12.61 L
Finally, the volume of the gas at standard temperature is 12.61 L.
Learn more about
Charles's law:
https://brainly.com/question/4147359
STP conditions:
brainly.com/question/26364483
brainly.com/question/8846039
brainly.com/question/1186356
#SPJ2
What are the 3 reactants necessary for photosynthesis
Answer:
Carbon dioxide
Water
Glucose
Answer:
To perform photosynthesis, we need three things: Carbon Dioxide WaterSunlightWhat is the difference between weight and mass?
Answer: it's easy just think about it:
Explanation:
weight: the weight of an object is the force acting on the object due to gravity.
mass: Mass is the amount of matter or substance that makes up an object.
in total: The mass of an object is a measure of the object's inertial property, or the amount of matter it contains. The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it.
Happy to help!
Feel free to ask any questions!
answer: mass is the amount of matter in a material(m)
and weight is a measure of how the force of gravity acts upon that mass(m*g)
acronyms for the first 20 elements
Answer:
HHeLiBeBCNOFNeNaMgAlSiPSClArKCaAnswer:
Acronym Elements Symbols
He Hydrogen H
has Helium He
light Lithium Li
brain Beryllium Be
but Boron B
can Carbon C
not Nitrogen N
offer Oxygen O
full Fluorine Fl
nine Neon Ne
subjects Sodium Na
must Magnesium Mg
all Aluminium Al
silly Silicon Si
people Phosphorus P
stop Sulphur S
calling Chlorine Cl
a Argon Ar
pope Potassium K
christ Calcium Ca
what is the amount of gold present in 15.5g of a pure gold ring? (Au=197)
Answer:
.0787 moles
Explanation:
I'm assuming you mean moles of gold present as the "amount."
This is a moles to moles calculation, so we set it up as such:
*Note that 15.5g Au is given to us, and 197 g / mol of Au is gold's molar mass.
15.5g Au * (1 mol Au / 197 g Au) = ?
We can evaluate the equation to get 15.5 / 197 to get .0787 moles of Au.
Plz I need help with my chemistry homework jJnsjs
answer
1.1 Carbon is the sixth element in the periodic table.
(IV A)
1.2 electric configuration: O⁸ (He²) 2s² 2p⁴ .
atomic number: 8
1.3 protons= 8 , electron = 7
1.4 oxygen has 6 valence electrons .
carbon has 4 valence electrons.
1.5 the answer is in the photo.
Which of the following statements is true?
A.
Protons are located outside the nucleus of an atom.
B.
Electrons do not have mass.
C.
Individual atoms can be seen with the naked eye.
D.
The nucleus of an atom contains protons and neutrons.
Reset
Answer:
Option D
Explanation:
The nucleus of an atom consists of both protons and neutrons
Answer:
d
Explanation:
the nucleus of an atom contains protons and neutrons.
1. What is the term for a process causing the particles contained in
a substance to be packed more closely together?
A. coefficient of expansion
B. contraction
C.expansion
D. packing
E. squeezing
2. A one liter sample of gas is heated under constant pressure from
100°C to 200°C. Its volume increases to 1.27 liters. On further
heating to 300°C, what would the volume of the sample be?
A. 1.00 liter
B. 1.27 liters
C. 1.54 liters
D. 1.81 liters
3. A 5-liter sample of gas initially at 50°C is observed to expand to
5.5 liters when the temperature is raised to 100°C. After further
increase in temperature, the volume is 6 liters. What is the
approximate temperature (within 50 degrees) of the final state of
the gas?
A. 50°C
B. 100°C
C. 150°C
D. 200°C
Please help
Answer:
1) contraction
2) 1.54 liters
3) 150°C
4) The gas expands proportionally to the increase in temperature
5) false
6) true
7)pentane
8) it has a boiling point around 35°
Explanation:
describe how vitamin A may be used in the body
Answer:
Vitamin A is important for normal vision, the immune system, and reproduction. Vitamin A also helps the heart, lungs, kidneys, and other organs work properly. There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products.
Answer:
Vitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucus membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye. Vitamin A promotes good eyesight, especially in low light. It also has a role in healthy pregnancy and breastfeeding.
:-))
Monsters are real, and ghosts are real too. They live inside us, and sometimes, they win - Stephen King.
━━━━━━━━━━━━━
Answer:
so what is the question?
where is the question?
thank you for free points. GBU.
A student uses a microscope to observe a single-celled organism that can move. The organism contains a nucleus and many chloroplasts. Based on the observations, the student claims the organism is not a bacterium. Which observations BEST supports the student's claim. * 1 point The organism is unicellular. The organism is able to move. The organism has a nucleus. The organism performs photosynthesis.
Answer:
The organism has a nucleus
Explanation:
According to this question, a student makes a claim that an observed organism is not a Bacteria. Organisms have been classified into two major domains based on their nucleus. Eukaryotic organisms have a well-defined double membrane nucleus while prokaryotes do not.
The organism being observed in this question posseses a nucleus and many chloroplasts meaning that the organism is most likely an EUKARYOTE. The observations that backs the student claim is that the organism has a nucleus. Bacteria is an example of prokaryotic organisms with no nucleus in their cell.
.
please help It's due today please
Answer:
i have no clue
Explanation:
Answer:
??????????
Explanation:
Which of the 3 sub particles of an atom, weighs the LEAST?
How many Valence electrons and energy shells does Ge have?
A.4 Valence Electrons and 6 Energy shells
B.7 Valence Electrons and 3 Energy shells
C.2 Valence Electrons and 6 Energy shells
D.4 Valence Electrons and 4 Energy shells
Answer:
D. 4 Valence Electrons and 4 Energy shells
Explanation:
Hello!
In this case, since finding the number of valence electrons and energy shells require the determination of the electron configuration for the element, knowing that germanium has 32 electrons (atomic number), we have:
[tex]1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^{10},4p^2[/tex]
We can see that the outermost energy shell is 4 which storages 4 electrons (2 from 4s and 2 from 4p); therefore, we infer it has 4 valence electrons and 5 energy shells, so the answer is:
D. 4 Valence Electrons and 4 Energy shells.
Best regards!
In a percentage composition investigation a compound was decomposed into its elements: 20.0 g of calcium, 6.0 g of carbon, and 24.0 g of oxygen. Determine the percentage composition of this compound
The percentage composition of this compound : 40%Ca, 12%C and 48%O
Further explanationGiven
20.0 g of calcium,
6.0 g of carbon,
and 24.0 g of oxygen.
Required
The percentage composition
Solution
Total mass of compound :
=mass calcium + mass carbon + mass oxygen
=20 g + 6 g + 24 g
=50 g
Percentage composition :
Ca-calcium[tex]\tt \dfrac{20}{50}\times 100\%=40\%[/tex]
C-carbon[tex]\tt \dfrac{6}{50}\times 100\%=12\%[/tex]
O-oxygen[tex]\tt \dfrac{24}{50}\times 100\%=48\%[/tex]
Identify the variables in the investigation: An investigation was done with an electromagnetic system made from a battery and wire wrapped around a nail. Different size nails were used. The number of paper clips the electromagnet could pick up was measured.
Answer:
Independent: sizes of nails
Dependent: number of paper clips
Controlled: Battery, wire and type of nails
Explanation:
An independent variable is a variable which when changes does not the effect the results of the experiment. It does not depends upon the dependent variable.
A dependent variable is defined as a variable which is affected when the independent variable is changed by the researcher or the experimenter. It depends greatly upon the independent variable.
While a controlled variable is that variable whose value is not changed in an experiment. It contains all the constants.
In the context,
the independent variable are : sizes of nails
the dependent variables are : number of paper clips
the Controlled variables are: Battery, wire and type of nails
HELP!!!!!! I will give you 15 points for this , please don’t guess
Answer:
Heterozygous refers to having inherited different forms of a particular gene from each parent.
Explanation:
How many moles are in 3.57 x 10 32
particles Ca?
Answer:
[tex]\boxed {\boxed {\sf 592,826,303.6 \ moles \ of \ Ca }}[/tex]
Explanation:
To convert from moles to particles, we must Avogadro's Number.
[tex]6.022*10^{23}[/tex]
This number tells us the number of particles (atoms, ions, molecules, etc.) in 1 mole of a substance. In this case, it is the particles of calcium in 1 mole of calcium.
[tex]6.022*10^{23} \ particles \ Ca / mole \ Ca[/tex]
We can use Avogadro's Number as a ratio or fraction.
[tex]\frac{6.022 *10^{23} \ particles \ Ca}{1 \ mol \ Ca}[/tex]
Multiply this by the given number of particles (3.57*10³²).
[tex]3.57*10^{32} \ particles \ Ca*\frac{6.022 *10^{23} \ particles \ Ca}{1 \ mol \ Ca}[/tex]
Flip the fraction so the particles of calcium will cancel out.
[tex]3.57*10^{32} \ particles \ Ca*\frac{1 \ mol \ Ca}{6.022 *10^{23} \ particles \ Ca}[/tex]
[tex]3.57*10^{32} *\frac{1 \ mol \ Ca}{6.022 *10^{23} }[/tex]
[tex]\frac{3.57*10^{32} \ mol \ Ca}{6.022 *10^{23} }[/tex]
[tex]592826303.6 \ mol \ Ca[/tex]
There are 592,826,303.6 moles of calcium in 3.57*10³² particles of calcium.
How many half-lives took place if I started with 125,000 atoms, and I now only
have 15,625 of the original atom?
The pH is given for three solutions. Calculate (H+] and [OH-] in each solution.
b. pH = 11.05
Plss show work
what is electrochemistry?
A. the study of photons in chemistry
B. the study of electricity in chemistry
C. the study of charge particles in chemistry
D. the study of valence-electrons in chemistry
Answer:
B. the study of electricity in chemistry
Explanation:
Electrochemistry is the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to another in a reaction known as an oxidation-reduction ("redox") reaction.
Answer:
B => Study of electricity in chemistry
Explanation:
Electrochemistry is the study of electricity associated with chemical oxidation-reduction reaction. It is divided into two distinct disciplines; electrolysis and Galvanic Process.
Electrolysis is a nonspontaneous process requiring an outside power source (typically a battery) to drive the chemical reactions. Applications include metal refining and generation of various gases (for collection) by chemical process.
Galvanic Process is a spontaneous chemical process generating electrical energy by taking advantage of the different properties of metals. Applications include batteries for many devices such as flash lights (Leclanche dry cell), alkaline button batteries for hearing aids, automobile batteries (lead storage batteries), the H₂/O₂ Fuel Cell battery, etc.
In general,
Electrolysis => Uses electrical energy (batteries) to drive chemical reactions
or,
Galvanic Process => Using chemical reactions to generate electrical energy
what is the atomic number of carbon