False.....................
classify the following elements under metals, non metals and metalloids, boron, zinc Mercury, silicon, oxygen, nitrogen, sodium
Answer:
Zinc mercury transition metal
Silicon boron metalloid
Oxygen nitrogen non metal
Sodium alkali metal
Explanation:
A sample containing 0.75 moles of CO2 would contain how many atoms?
Answer:4.5 ×10^22)
Explanation:
no. of particles =no. of mole×avogadro's number of particles no. of particles =0.75×6.02×10^23 no. of particles =4.5 ×10^22
Use your knowledge of atoms, bonding, and the periodic table to complete the chemical equation .”CH4 + O2
and predict the products of the chemical reaction on your paper. Label this equation “Initial Prediction.
Answer:
CH4 + O2 = CO2 + H2O.
Answer:
CH4 + O2 = CO2 + H2O.
Explanation:
A mixture of helium, nitrogen and oxygen has a total pressure of 781 mmHg. The partial pressure of helium is 331 mmHg, and the partial pressure of nitrogen is 222 mmHg. What is the partial pressure (in mmHg) of oxygen in the mixture?
Answer:
Partial pressure of O₂ = 228 mmHg
Explanation:
The mixture is made of three gases, He, N₂ and O₂.
Total pressure of it, is 781 mmHg.
There is a law from gases, that indicates the sum of partial pressures of each gas in a mixture will be the total pressure of the system. In conclussion:
Partial pressure of He + Partial pressure of N₂ + Partial pressure of O₂ = Total pressure.
331 mmHg + 222 mmHg + Partial pressure of O₂ = 781 mmHg.
Partial pressure of O₂ = 781 mmHg - 331 mmHg - 222 mmHg
Partial pressure of O₂ = 228 mmHg
Which substances in the list can be used to write a complete combustion reaction? (4 points)
O 1, 2, and 3
O 2, 3, and 6
O 1, 4, and 5
O 1, 2, and 5
Answer:
B. 2, 3 and 6
Explanation:
The primary materials for a chemic combustion reaction are Fuel + O2 → CO2 + H2O!
Hope this could help! （*＾ワ＾*）
Answer:the answer is B
Explanation:
Calculate the concentration of a 220 g solution of calcium chloride (CaCl2) that has a volume of 11 L
Answer: The concentration of the solution is 0.18 M
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]V_s[/tex] = volume of solution in L
moles of [tex]CaCl_2[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{220g}{111g/mol}=1.98mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{1.98mol}{11L}=0.18M[/tex]
Therefore, the concentration of the solution is 0.18 M
A physical change to a substance
can never be reversed
increase or decrease the mass of a substance
changes to type of matter the substance is made of
changes one or more of the physical properties of a substance
Answer:
4th one
Explanation:
a physical change is something u can see, so if the substance changes its properties then thats a physical change.
Explain how a long-term environmental change can lead
to the development of a new species.( its a paragraph
Answer:
Humans are modifying the world in many ways, and not all of them for the better. The changes we cause are often severe challenges to animals, plants and microbes in nature, from the introduction of pathogens or exotic invasive species to adding toxic substance or excessive nutrients, or causing climatic change. Often several changes occur at once. Nelson Hairston's lab focuses on freshwater environments, especially lakes and ponds, where some of the species present respond to environmental change with decreases in their numbers, even to the point of extinction, while others may benefit to excess, becoming so dominant that they present problems, as in the case of harmful algal blooms stimulated by nutrient enrichment or climate warming. Hairston's lab studies how individual species, food webs, and whole ecosystems are altered when the environment changes.
One way that some freshwater organisms respond to environmental change is to evolve rapidly. A marked change in the environment favors some characteristics of plants, animals and microbes over others. These character differences are often genetically based so that favored characteristics may increase in the next generation. The shorter the generation time, the faster this evolutionary change can occur. For example, tiny but abundant plankton, eaten by fish and other larger animals, can become adapted to the changed environment within a few years because their generation time is only a few days. Hairston's lab has shown that planktonic "water fleas" (Daphnia), major consumers of suspended algae in lakes, evolved to be tolerant of harmful algae within a decade of the appearance of blooms. This rapid evolution (termed "evolutionary rescue" in conservation biology) raises many intriguing questions, for all environments, not just freshwater: To what extent can we rely on species adapting rather than going extinct when their environment changes? How does the evolution of a species that plays a critical ecological role alter the interactions it has with other species, and the functioning of the entire ecosystem?
An alpha particle is composed of He2+ ions?
true or false
Answer: The given statement is False.
Explanation:
Alpha particle is a helium nuclei.
Alpha particles are produced when a larger nuclei decays into smaller nuclei in radioactive decay. Alpha particles have mass number and atomic number as 4 and 2 respectively.
General representation of alpha decay :
[tex]^A_Z\textrm{X}\rightarrow ^{A-4}_{Z-2}\textrm{Y}+^4_2\textrm{He}[/tex]
Thus the given statement that alpha particle is composed of [tex]He^{2+}[/tex] ions is False.
The statement of [tex]\rm He^2^+[/tex] ions has formed the alpha particles is true.
Alpha particles are particles that have been similar to the He-4, with the presence of two protons and two neutrons. The alpha particles have the absence of electrons and have been formed during the alpha decay.
[tex]\rm He^2^+[/tex] has been the ion of He with the positive charge indicating the loss of 2 electrons. Thus, in [tex]\rm He^2^+[/tex], there has been 2 protons, 2 neutrons, and 0 electrons.
The atomic configuration of [tex]\rm He^2^+[/tex]has been similar to the alpha particles. Thus, the statement stating, "the alpha particles to be composed of [tex]\rm He^2^+[/tex]ions " is True.
For more information about the alpha particles, refer to the link:
https://brainly.com/question/1685421
1.25 x 10^25 atoms of magnesium = ? moles of magnesium
if 13 moles of Fe react, what is the mass of FeS produced?
Answer:
1144 g of FeS
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
Fe + S —> FeS
From the balanced equation above,
1 mole of Fe reacted to produce 1 mole of FeS.
Therefore, 13 moles of Fe will also react to produce 13 moles of FeS.
Finally, we shall determine mass of 13 moles of FeS. This can be obtained as follow:
Mole of FeS = 13 moles
Molar mass of FeS = 56 + 32
= 88 g/mol
Mass of FeS =?
Mass = mole × molar mass
Mass of FeS = 13 × 88
Mass of FeS = 1144 g
Therefore, 1144 g of FeS were obtained from the reaction.
I need help with the balancing one
Answer:
2Na2S + Cd(NO3)2 ---> CdS + 2NaNO3
The coefficients therefore are 1,1,1&2
What is the meaning of social group
Answer:
In the social sciences, a social group is two or more humans who interact with one another, share similar characteristics, and have a collective sense of unity. This is a very broad definition, as it includes groups of all sizes, from dyads to whole societies.
Explanation:
Answer:
The meaning of social group is two or more people who interact with one another, share similar characteristics, and collectively have a sense of unity.
Explanation:
Hope this helped
When collecting temperature as a function of time for the reaction of KOH with HCL, which time is most significant
Answer:
At the completion of reaction.
Explanation:
The time when the reaction take places is the most significant time for measuring temperature of the solution because on this time the temperature will decrease or increase. Some reactions releases heat energy upon completion we called them exothermic reactions whereas some absorb heat energy from the surrounding, decreases the temperature which is known as endothermic reaction so measuring temperature at the completion of reaction is the correct time.
:)
Why is water called.compound
Answer:
because it's composed of two elements, hydrogen and oxygen. water is technically a molecular compound tho, for it has two hydrogens.
Living organisms need energy to carry on their life processes. Photosynthesis is a process that allows for photosynthesizing organisms, such as algae and green plants, to produce their own materials for energy production and survival. This process can be outlined as a simplified chemical equation containing reactants (goes into the process) and products (made/comes out of the process).Using your knowledge of science and figures above, select the choice that accurately expresses photosynthesis.
the correct combo is C
We know sunlight is key factor in photosynthesis so A and D are out.
we also know plants get their bulk by breaking up co2 and using the carbon which releases oxygen as a byproduct so B is also out of the question.
two types of subatomic particles in the nucleas of an atom
Explanation:
protons and neutrons.....
...
Answer:
The subatomic particles are Protons and Neutrons.
Formula for tricarbon hexoxide
list 2 ways mechanical energy can be transformed into non-mechanical energy ?
Answer:
One is the classic example of friction. When two surfaces rub together, they generate thermal energy, or heat. This is a transformation of the mechanical kinetic energy of the objects into the thermal non-mechanical energy (which is small-scale kinetic energy).
Mechanical energy can be used to overcome friction or lost in form of heat in machine parts. Friction and heat are two non-mechanical energy.
Transformation of mechanical energy into non mechanical energy
Based on the principle of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another.
Two ways mechanical energy can be transformedThe two ways mechanical energy can be transformed include the following;
FrictionHeatMechanical energy can be used to overcome friction or lost in form of heat in machine parts, in this process, the mechanical energy (kinetic energy) would be converted into other forms of energy such as heat.
Learn more about conservation of energy here: https://brainly.com/question/166559
Mr Singh is cooking using wo pans of oiling water. Both pans are made of steel, but one pan has a much thicker base than the other pan. Explain how energy is transferred through the metal pans. Write about particles in your answer.
Answer:
See explanation
Explanation:
When either pan is heated, energy is transferred via conduction. Conduction is the process by which heat is transferred through a material, the average position of the particles remaining the same.
When the pans are heated, the particles in each pan vibrate faster and transfer this energy rapidly to neighboring particles.
The pan with a thicker base has more particles in it than the pan with lighter weight base. Note that, The rate of heat transfer is inversely proportional to the thickness of the material in question. Hence, the thicker the base, the more the number of particles present and the longer the time it takes for the food to cook.
En una planta de energía, se produce CO2 gracias a la reacción de combustión del material orgánico con oxígeno para producir CO2, SO2, SO3, NO, NO2 y H2O que son los causantes del efecto invernadero, el SO2 reacciona con H2O para formar H2SO3, causante de la lluvia ácida. En condiciones de gas ideal el SO2 se encuentra a una temperatura de 100°C y 0,5 atm de presión, el volumen ocupado generalmente es de 25 L. 5. La ecuación para hallar el número de moles debe ser: a. Gases ideales: relación entre todas las variables que influyen sobre los gases b. Boyle: relación entre volumen y presión c. Charles: relación entre el volumen y la temperatura d. Gay Lussac: relación entre la presión y la temperatura
Answer:
a. Gases ideales: relación entre todas las variables que influyen sobre los gases
Explanation:
La ecuación del gas ideal da la relación entre las variables; presión, volumen, temperatura y número de moles.
Según la ecuación del gas ideal; PV = nRT
P = presión del gas
V = volumen del gas
n = Número de moles del gas
R = constante de gas
T = temperatura del gas
El número de moles de SO2 se obtiene de;
n = PV / RT
n = 0,5 * 25 / 0,082 * 373
n = 12,5 / 30,586
n = 0,41 moles
2. This chart describes several characteristics of human civilizations.
(6.04)
Characteristics of Human Civilizations
Stable Food Supply
?
Developed Systems of Writing
Which phrase best completes this list?
A. Created militaries
B. Complex social structures
C. Use of fire for protection
D. Declining population
True or False; the atomic number always equals the number of protons, neutrons and electrons found in an atom.
"" ANSWER""
Protons are values of atomic numbers that do NOT change, that is, they are located inside the nucleus of the atom, whereas electrons are located in the electrosphere that can gain or lose electrons, the electron has a negative charge and the Proton positive, that is, if in any atom it wins an electron the atom will be negative and if the atom loses it will be positive because we already know that the number of protons does not change. To calculate the number of neutron we have to make the number of rounded atomic mass which becomes mass less the number of protons for example oxygen gas has 8 protons which is the atomic number and has atomic mass 15,999 which rounding up to 16 to find the number of neutrals we do 16-8 = 8 so now we know that oxygen has: 8 protons, 8 electrons and 8 neutrons but the values will not always be the same but the possibility of protons and neutrals having the same value is 75% by my count .
● ○ ● RULES ○ ● ○ ●
Atomic number = number of protons
Atomic mass ROUNDNESS = mass
Number of neutrons = number of protons - mass number
OBSERVATION- EXPLANATION FOR STUDENTS OF 9 YEARS BECAUSE IN THE HIGH SCHOOL UP SOME CHANGES CHANGE.
■■ GOOD STUDIES ■■
What does chemistry mean?
Answer:
The definition of chemistry is a branch of science that deals with the form and properties of matter and substances or the interaction between individuals.
See photo! Calculating mass and percentage yields.
Answer:
see above
Explanation:
check for cfe's
!!!PLEASE HELP!!!
3. If a convergent boundary involves a continental landmass and an ocean basin, what is the result?
A: A chain of volcanic mountains will form on the edge of the continent or just off shore, a deep
ocean trench will form off shore.
B: The land will fold and fault, forming high mountain ranges.
C: The land
at the edge of the continent will buckle, causing the formation of a trench.
D: There will be frequent earthquakes, but no other evidence of crustal movement.
Answer:
A
Explanation:
If a convergent boundary involves a continental landmass and an ocean basin, a subduction zone forms. Subduction occurs where a plate moves underneath the other.
what are the difference between hemogeneous mixture and heterogeneous mixture ??
Answer:
Refer to attached file below
Hope it helps..
Have a great day :P
"pure water does not conduct electricity. But some tap water probably can. Which best explains this?" a . Tap water is H20 b . Pure water is H20 c . Some tap water has minerals, such as iron in it.
Explanation:
"pure water does not conduct electricity. But some tap water probably can."
The reason why pure water does not conduct electricity is due to the absence of mineral and metal containing salts. Pure water is made up of only Hydrogen and oxygen atom as represented by the formula; H2O
Tap water on the other hand are most likely able to conduct electricity due to the presence of these ions. They may arise from impurities or during treatment processes.
The correct options are;
b . Pure water is H2O
c . Some tap water has minerals, such as iron in it.
Can someone tell me if these are right? I am supposed to be decoding this for my escape room but it seems to be wrong.
Answer:
Q1 is A.
Q2 is right
Q3 is D.....I dont
really know about this one
Q4 is right
1. A wave has a frequency of 800 Hz and a wavelength of 2000 cm. What speed
is this wave traveling?
Answer:
V=f*(wavelength)
V= (800)(20m)
16000m/s
Explanation: