Answer:
see explanation
Explanation:
number of moles = mass ÷ relative formula mass
e.g.
Calculate the number of moles of carbon dioxide molecules in 22 g of CO2.
Ar (relative atomic mass) of C = 12, Ar of O = 16
Mr (relative formula mass) of carbon dioxide = 12 + 16 + 16 = 44
number of moles = 22 ÷ 44 = 0.5 mol
When piece of very hot metal releases energy into a cup of water, if the temperature of metal drops
by 426.7°C, and the final temperature of the metal is 31.2°C, what was the initial temperature of
the metal?
Answer: The answer is 457.9
Explanation: Realistically all you have to do is add both of the temperatures and then you can figure out the original heat. Since the heat drops 426.7 degrees and it comes to 31.2 degrees its 426.7 + 31.2 = 457.9.
An ion has 56 protons, 54 electrons, and 81 neutrons. What is its atomic #?
Answer:
110.91982
The element is probably Barium
The atomic number of an atom is equal to the number of protons it has. In this case, the ion has 56 protons. Therefore, the atomic number of the ion is 56.
The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (np) or the number of protons found in the nucleus of every atom of that element. The atomic number can be used to uniquely identify ordinary chemical elements. In an ordinary uncharged atom, the atomic number is also equal to the number of electrons.
For an ordinary atom which contains protons, neutrons and electrons, the sum of the atomic number Z and the neutron number N gives the atom's atomic mass number A. As there are 56 protons thus the atomic number of the ion is 56.
Learn more about atomic number,here:
https://brainly.com/question/16858932
#SPJ3
Calculate the medullary index of a hair whose diameter is 110
microns wide and whose medulla measures 58 microns. Is this
a human or animal hair?
The medullary index of hair is the ratio of medullary diameter to the diameter of hair. Thus the medullary of hair with 110 microns and medulla diameter of 58 microns is 0.533. This is an animal hair.
What is hair medullary index?Medullary index of hair is the ratio of diameter of the medullary part and the diameter of the hair strand. From this value, we can identify whether the sample hair is of humans or animals.
Hair is made proteins called keratin. The protein structure of hair vary from human to human even one hair strand to the other and similar way it is different in animal hair too.
The hair strand of humans are thin than the hair strands of animals. Thus the medullary index of humans is 0.333 or less. If the index is 0.50 or greater it is of animals.
Here the diameter of hair is 110 microns and that of medulla is 58 microns thus medullary index is 58/110 = 0.55 microns. Which means that it is an animal hair.
To find more about medullary index, refer the link below:
https://brainly.com/question/1658827
#SPJ2
Why silicone and germanium are useful in electronic industry????
Answer:
: Each has four valence electrons, but germanium will at a given temperature have more free electrons and a higher conductivity. Silicon is by far the more widely used semiconductor for electronics, partly because it can be used at much higher temperatures than germanium
Explanation:
have a great day
which factor increases as the efficiency of a machine increases
Answer:
Because all machines lose input work to friction, one way to improve the efficiency of a machine is by reducing friction. Oil is used to reduce friction between the moving parts of car engines. The use of oil makes engines more efficient. Another machine that loses input work is a bicycle.
Explanation:
Hope this helps.
The factor which increases as the efficiency of a machine increases is: work output.
Efficiency can be defined as a ratio of work (energy) output to work (energy) input.
Mathematically, the efficiency of a machine is given by the formula:
[tex]Efficiency = \frac{W_O}{W_I} \times 100[/tex]
Where:
Wo is the work output.Wi is the work input.Work can be defined as the amount of energy required to move an object from one point to another.
Hence, the work done by a machine is the product of the perpendicular force acting on the machine and the distance it covers or travels.
Ideally, the work output of a machine is highly dependent on its efficiency and as such, it is a factor which increases as the efficiency of a machine increases
Read more: https://brainly.com/question/22599382
Can someone please help me
Explanation:
Solids have a definite shape and volume. Liquids have a definite volume, but take the shape of the container. Gases have no definite shape or volume.
The kinetic theory of matter (particle theory) says that all matter consists of many, very small particles which are constantly moving or in a continual state of motion.
Answer this question will give brainliest
Answer:
heat energy
Explanation:
heat give energy so heat carriers energy
Describe the endogenous pathways of cholesterol metabolism.
Explanation:
Endogenous pathway for lipid metabolism: VLDL is formed in the liver from triglycerides and cholesterol esters. ... In the liver, LDL is converted into bile acids and secreted into the intestines. In non hepatic tissues, LDL is used in hormone production, cell membrane synthesis, or stored.
A sample of 8.00 g of Mg(OH)2 is added to 24.2 mL of 0.205 M HNO3. How many moles of Mg(OH)2 our present after the reaction is complete?
The amount of Mg(OH)2 present after the reaction is complete is 0.136 moles of Mg(OH)2.
The equation of the reaction is;
2HNO3(aq) + Mg(OH)2(aq) -------> Mg(NO3)2(aq) + 2H2O(l)
Number of moles of Mg(OH)2 = 8.00 g/58 g/mol = 0.138 moles
Number of moles of HNO3 = 0.205 M × 24.2 mL/1000 = 0.00496 moles
Given that;
2 moles of HNO3 reacts with 1 mole of Mg(OH)2
0.00496 moles of HNO3 reacts with 0.00496 moles × 1 mole /2 moles = 0.00248 moles of Mg(OH)2
Hence, Mg(OH)2 is the reactant in excess.
The amount of Mg(OH)2 remaining = Amount present - Amount reacted
Hence; 0.138 moles - 0.00248 moles = 0.136 moles of Mg(OH)2
Learn more: https://brainly.com/question/9743981
Select the correct answer from the drop-down menu.
Which of these is an example of chemical digestion?
(a person cutting food into small pieces with a knife)
(B
saliva breaking down molecules in the mouth)
(C bones leaching calcium into the bloodstream
)
(D a blender mixing solid food into a paste)
Answer:
B. Saliva breaking down molecules in the mouth
Explanation:
I'm pretty sure it's this because saliva contains enzymes and enzymes use chemicals to break down food in your mouth. For example, your mouth has an enzyme called amylase which helps to break down starches.
Answer:
B. Saliva breaking down molecules in the mouth
Explanation:
I'm pretty sure it's this because saliva contains enzymes and enzymes use chemicals to break down food in your mouth. For example, your mouth has an enzyme called amylase which helps to break down starches.Explanation:
Write each formula to solve for density, volume and mass.
please help!! will have a thanks and brainliest
Answer:
A
Explanation:
I just did learned all about this
How many total atoms are in this formula?
2MgSO4
Which statement(s) correctly compare the masses of protons, neutrons, and electrons? Select two options.
1. Protons and neutrons have similar mass.
2. Protons and electrons have similar mass.
3. Neutrons and electrons have similar mass.
4. Protons are smaller than a neutron or an electron.
5. Neutrons are smaller than a proton or an electron.
6. Electrons are smaller than a proton or a neutron.
Answer:
6 Electrons r smaller than a proton or a neutron
Answer:
1st and last one
Explanation:
If you have 10 tasks complete to finish a project‚ how many days will you need to spend working on this course if you spend five days on each task?
A.p.e.x l.e.a.r.n.i.n.g reading skills and strategies
Answer:
Well 50 of course
Explanation:
5 days per tasks is like saying 10 times 5 which is 50.
Limestral flour (calcium carbonate) is a weak base used for at a few years of intervals Neutralize the acidification that takes place by lakes and woodland. Would not be a good idea that instend Using the stronger base sodium hydroxide and then be able to use a little less amount?
Answer:
Well, no.
Explanation:
NaOH is a base which is found in soap, and other detergents which gives it the slippery feel, because, it is a really strong base. Applying this to lakes and woodland could make the water and woodland really concentrated which could make them harmful for domestic and industrial use
why did rutherford think that all of the alpha particles would go straight through?
5 Facts about Geology
Studying the brightness of a star can help scientist determine what part of the life-cycle a star is in.
Answer:
yes
Explanation:
Please someone help!!!!!!!!
Answer & Explanation:
For the water to H2 and O2 problem:
1) Reactant is H20, it is to the left of the arrow.
2) Products are H2 (gas) and O2 (gas) because it is to the right and what is created.
For the CO2 + water -> Glucose + Oxygen problem:
1) Reactant is CO2 and H2O, it is to the left of the arrow and what is being changed.
2) Products are C6H12O6 (glucose) and O2 (gas) because it is to the right and what is created.
How do the metals in group 1 compare with the transition metals?
Answer:
Group 1 metals and transition metals are different from each other, mainly based on the colour of the chemical compounds that they form. The key difference between group 1 metals and transition metals is that the group 1 metals form colourless compounds, whereas the transition metals form colourful compounds.
Why is newton's first law of motion considered a law and not a theory?It is an unsupported idea.It is based on multiple observations.It has never been tested.It was validated by a singular experiment.
Answer: B. It is based on multiple observations.
Explanation:
Newton's first law of motion is considered a law and not a theory because it is based on multiple observations.
What is an observation?
Observations are defined as a set of statements or facts which are recorded while conducting an experiment.Observations are made through sensing changes in the variables of the experiment.
It is specifically defined as an act of knowing or recording the changes in the variables of the experiment.Recording observations holds importance as recording observations avoid the experiment to be repeated over and over again.
It is important to note down observations so that the testing of hypothesis is made easier.There are four types of observations .Observations need to be descriptive and must be written in complete sentences and should include all the numerical data of the experiment.
Learn more about observation,here:
https://brainly.com/question/28041973
#SPJ5
Answer the question below. Use the rubric in the materials for help if needed.
Compare and contrast ionic and covalent bonds by explaining what the electrons do when bonding occurs. Use details to support your answer.
Answer:
..
...
....
Explanation:
hop it helps.....
Sabrías citar al menos tres elementos gaseosos en estado natural
Answer:
a change in the level of consumer income
Explanation:
What is a compound?
a combination of two or more substances that are not chemically combined
a combination of two or more elements that are combined in a certain ratio
Answer:
a combination of two or more elements that are combined in a certain ratio
Explanation:
A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound.
any push or pull is called
Answer:
A Force.
Explanation:
A force is a push or pull upon an object resulting from the object's interaction with another object. ... Forces only exist as a result of an interaction.
How do I do unabbreviated electron configurations?
Answer:
In shorthand electron configuration, the electron configuration starts with the symbol of the noble gas in the previous period, followed by the additional configuration of the electrons for the given element. For example, aluminum has the atomic number 13, which is the number of protons in the nuclei of its atoms.
if you need more help go to you-tube and search up Abbreviated Electron Configurations and it's by EisleyChem
what is the density of an object with a height of 1 and a mass of 36
you will divide 36 by 1 and multiply 2 on both sides which makes 72 by 2 so 2into 1 is 2 and 2 into 36 is 72
The density of a liquid is 6.0g/cm3 , when it fills a container of volume 300cubic centimeters . What is the mass of the liquid in the container?
Answer:
1800g
Explanation:
b/c d=m/v
m=dv
m=300×6=1800g
The mass of the liquid in the container is equal to 1800 g.
What is the density?The density of an object can be described as the mass per unit volume of the object. The average density of any substance equals the total mass of the substance divided by its total volume.
The mathematical formula of the density can be expressed as follows:
The density of material = Mass/Volume
Mass = density × Volume
The S.I. unit of the density of any substance is Kg/m³ and it is an intrinsic property. If the size of the substance increases, the mass increases as well but the density of the substance will stay constant.
Give, the density of the liquid, d = 6.0 g/cm³
The volume of the container, V = 300 cm³
The mass of the liquid = 6 ×300 = 1800 g
Therefore, the mass of the liquid is equal to 1800 g.
Learn more about density, here:
brainly.com/question/15164682
#SPJ5
