Answer:
Cells are the basic building blocks of living things. The human body is composed of trillions of cells, all with their own specialised function. Cells are the basic structures of all living organisms. Cells provide structure for the body, take in nutrients from food and carry out important functions.
an object moving with a speed of 5m/s has a kinetic energy of 100J what is the mass of the object
Answer:
k. e. = 1/2 mv^2
100 = 1/2 * m * 5^2
100 = 1/2 * m * 25
m = 100 *2/25
m = 8 kg
hope it helps you
Explain five physical and/or chemical properties that you need to consider for the substances before using them as construction materials for buildings
Answer: There are many properties of a metal which is taken into consideration when it is used for construction
Explanation:
The properties can be physical, chemical, et cetera. The physical properties that is considered are:
1. Durability: It can be defined as the property of the material to withstand the atmospheric pressure and other factors.
2. Density: The ratio of mass by volume of a material (homogeneous material) is called as density.
3. Fire resistance: The ability of the material to withstand in fire without changing its size or shape.
4. Weather resistance: The ability of the material to withstand the weather which could be variable round the year.
5.Water absorption: The ability of the material to absorb water and retain it.
I don't really understand this worksheet question.
what kind of chemical bond is established in hydrochloric acid?
Answer and Explanation:
HCl, also known as hydrochloric acid, has a covalent bond. The hydrogen (H) atom shares an electron with the chlorine (Cl) to form the bond.
8. __H2 + __O2-> __H2O
9. __K2SO4 + __H2-> __H2SO4 + __K
10. __NO2 + __H2O-> __HNO3 + __NO
Anser:
Explanation:
hope this helps
What can help overcome a positive enthalpy of solution and allow a solid
solute to dissolve in water?
A. A decrease in entropy
B. A large amount of energy released
C. A large amount of energy absorbed
D. An increase in entropy
Answer: D. An increase in entropy
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.
For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.
To overcome a positive enthalpy of solution and allow a solid solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.
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What are the rows of elements called on the periodic table?
Answer:
"The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups."
Explanation:
I GIVE OUT FREE POINTS
How would you describe the appearance of homogeneous mixture? A. Homogeneous mixtures do not have a uniform composition. B. Homogeneous mixtures have a uniform appearance. C. Homogeneous mixtures are not distributed evenly. D. Homogeneous mixtures have two phases
Answer:
i think its c somebody correct me if im wrong. but hope this help
Explanation:
If you find a chemical in the lab and are unsure of
its identity, what is the best way to find out what it
is?
Answer:
C. read the label on the container
Explanation:
What information is found in an SDS? Check all that apply.
A. the identification of the chemical
C. the chemical and physical properties of the substance
D. the first-aid measures to take if an accident occurs involving the chemical
Answer:
C
Explanation:
just did it
Structural formula of 2 ethyl, 4 methyl-Heptane
Which feature does an iron metal have?
O electrons that transfer between atoms to make cations and anions
O a sea of electrons
O firmly bonded electrons
O electrons shared between single pairs of atoms
Answer:
a sea of electrons
Iron metal has a sea of electrons.
Iron metal is an element which possesses a sea of electrons as a result of it
containing cations which are usually surrounded by electrons which move at
a very fast pace .
This property makes Iron metal to be reactive when exposed to air( oxygen)
and it then forms various compounds such as Iron(II) oxide, Iron(III) oxide and
rust.
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The creation of carbon monoxide is an effect. What is one cause?
A. the regrouping of the atoms in table salt
B.the burning of fossil fuels
C.cleaning swimming pools
D.operating a stove
Answer:
Your answer is going to be B. the burning of fossil fuels
Explanation:
This is because carbon monoxide is extremely toxic for us humans. An example of this could be pollution. Hope this helps! :)
5. Describe the effects of photons of light on an electron of the hydrogen atom
Answer:
How do atoms give off light?
Atoms emit light when they are heated or excited at high energy levels. The color of light that is emitted by an atom depends on how much energy the electron releases as it moves down different energy levels. ... It shows the electron moving down energy levels.
Explanation:
In which highlighted section of the periodic table in the diagram provided above are the elements whose atoms have 1 valence electron located?
A) a
B) b
C) c
D) d
Answer:
B.
Explanation:
An object has a mass of 26.94 grams and a volume of 2.568 cubic centimeters. What material is it likely to be
made of?
Substance iron gold silver copper
Density (g/cm) 7.874 19.32 10.49 8.92
a. Silver
c. Iron
b. Gold
d. Copper
Answer:
a) silver
Explanation:
Given data:
Mass of object = 26.94 g
Volume of object = 2.568 cm³
Which subject is this = ?
Solution:
Formula:
d = m/v
by putting values
d = 26.94 g/ 2.568 cm³
d = 10.49 g/cm³
Densities of objects: g/cm³
iron = 7.874
gold = 19.32
silver = 10.49
copper = 8.92
Thus, given object is silver.
27.2Pb(NO3)2 --> 2Pb0 + 4NO2 + O2
O A. Synthesis
B. Single displacement
C. Decomposition
D. Combustion
What happens to valence electrons in ionic bonding?
Answer:
they are either donated to or taken by another atom to achieve octet arrangement
Explanation:
for example Na+ and Cl- .. they both have one extra and one less electron .
so they donate and receive one electron to/from each other to achieve the octet arrangement ..
What three types of particles make up an atom? What are their charges?
Answer:
Protons, neutrons, and electrons are the three main subatomic particles found in an atom. Protons have a positive (+) charge. An easy way to remember this is to remember that both proton and positive start with the letter "P." Neutrons have no electrical charge.
Answer:
Protons, positive charge
Neutrons, neutral
Electrons, negative charge
Explanation:
Select the correct answer from each drop-down menu.
Researchers stationed at different areas on a mountain and in a tunnel midway through the mountain boiled water at the same time. Even though the water at every station was at the same temperature, the pot at the top of the mountain started boiling before the others. Why?
Water boils when the vapor pressure is
the atmospheric pressure. The atmospheric pressure
at the top of the mountain.
Water boils when the vapour pressure is least the atmospheric pressure.
The atmospheric pressure is equal at the top of the mountain.
What is atmospheric pressure?The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth.
As we go up in altitude the air pressure becomes less. When the pressure decreases, it takes less energy to get the water molecules to escape the surface. So the temperature is less than it would be at sea level.
Air pressure is higher or greater at the bottom of a mountain. This is because the height of the air above that level is thicker than at the top.
Pressure is given by the equation, P=rho*g*h, where rho is the air density, g is the gravity value and h is the thickness of the air layer on top of the level where we are considering the pressure.
Therefore, as we can see, at the bottom of the mountain, the thickness h of air is greater, and so is the pressure.
Hence, water boils when the vapour pressure is least the atmospheric pressure and the atmospheric pressure is equal at the top of the mountain.
Learn more about the atmospheric pressure here:
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Compare and contrast atoms and molecules. Cite specific examples from the readings, as well as what you may already know, to support your comparison.
Answer:
The main difference between an atom and a molecule lies in the size: while the atom is the smallest unit into which matter can be divided into any of its states, a molecule is the union of a group of atoms, that is, this composed of several atoms. Thus, for example, a water molecule is composed of two hydrogen atoms and one oxygen atom (H2O). Therefore, it can be said that atoms are the smallest unit in which the chemical elements of the world can be divided, while molecules are the particles of matter that are formed through the combination of these elements.
5. CaCO, - CaO+CO,
Reaction Type
Answer:
(a) Decomposition: A substance breaks down to smaller species. [e.g. CaCO3(s) → CaO(s) + CO2(g) Decomposition of limestone to calcium oxide (quicklime) and carbon dioxide on heating.]
Answer these three please! Thank you <3333
(I will give brainliest)
Answer:
Explanation:
21:B 22:B
determine the theoretical yield.
aluminum metal reacts with aqueous nickel II sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. in this reaction 108 grams of aluminum were combined with 464 grams of nickel II sulfate to produce 274 grams of aluminum sulfate.
The question is incomplete, the complete question is;
In this stoichiometry problem, determine the percentage yield:
Excess aluminum metal reacts with aqueous nickel(II) sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. In this reaction 108 g of aluminum were combined with 464 g of nickel(II) sulfate to produce 274 g of aluminum sulfate.
Answer:
80%
Explanation:
The correct equation for this reaction is;
2Al(s) + 3NiSO4(aq) --------> Al2(SO4)3 + 3Ni(s)
We already know that Al is in excess then NiSO4 is the limiting reactant.
Hence, Number of moles in 464 g of NiSO4 = mass/ molar mass
Molar mass of NiSO4 = 155 g/mol
Number of moles = 464g/155g/mol = 2.99 moles
Number of moles of Al2(SO4)3 = mass/molar mass
molar mass = 342 g/mol
So, Number of moles = 274g/342g/mol = 0.8 moles
Given the stoichiometric reaction equation;
3 moles of NiSO4 yields 1 mole of Al2(SO4)3
2.99 moles of NiSO4 yields 2.99 * 1/3 = 1 mole of Al2(SO4)3
percentage yield is given by; actual yield/ theoretical yield * 100/1
actual yield = 0.8 moles of Al2(SO4)3
Theoretical yield = 1 mole of Al2(SO4)3
Hence;
% yield = 0.8/1 * 100 = 80%
define the clinical thermometer
Answer:
a small medical thermometer with a short but finely calibrated range, for taking a person's temperature.
Answer:
Thermometer which are used in clinical to measure the temperature of human body is called clinical thermometer.
CARDS
In a science experiment, Marisa concludes that no chemical reaction has occurred. What evidence would support
this conclusion?
A. the mass and total number of atoms were conserved
B. no energy were released
C. a new element was created
D. no new substance was formed
Answer:d
Explanation:
How many elements, compounds and atoms are in CH3COOH
Write one paragraph to summarize Strengths and Weaknesses of Acids and Bases.
Answer:
Explanation: I can't give you the answer you with the sentence but i will help you the best i can
One qualitative measure of the strength of an acid or a base solution is the pH scale A logarithmic scale that relates the concentration of the hydrogen ion in solution.
PLEASE HELPPP!!!!!! ASAP!!!!
Which of the following best describes cations? Question 19 options: A) They're negatively charged because they lost an electron. B) They're positively charged because they gained an electron. C) They're positively charged because the number of electrons remained the same. D) They're positively charged because they lost an electron.
Answer:D
Explanation:trust me bro
Answer:
D
Explanation: I took the test
List four greenhouse gases in the atmosphere. For each gas, describe its prevalence in the atmosphere, its natural sources, its human-induced sources, and how its concentration in the atmosphere might be changing.
Answer: Carbon Dioxide, Methane, Nitrous Oxide and Fuorinated Gases
Explanation:Carbon dioxide (CO2): Carbon dioxide enters the atmosphere through burning fossil fuels (coal, natural gas, and oil), solid waste, trees and other biological materials, and also as a result of certain chemical reactions (e.g., manufacture of cement). Carbon dioxide is removed from the atmosphere (or "sequestered") when it is absorbed by plants as part of the biological carbon cycle.
Methane (CH4): Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.
Nitrous oxide (N2O): Nitrous oxide is emitted during agricultural and industrial activities, combustion of fossil fuels and solid waste, as well as during treatment of wastewater.
Fluorinated gases: Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes. Fluorinated gases are sometimes used as substitutes for stratospheric ozone-depleting substances (e.g., chlorofluorocarbons, hydrochlorofluorocarbons, and halons). These gases are typically emitted in smaller quantities, but because they are potent greenhouse gases, they are sometimes referred to as High Global Warming Potential gases ("High GWP gases").
PLZ HELP!
Why do we use ramps (inclined planes) to help us move objects?
Plz nothing from the internet :D
