Answer:
70
Explanation:
The atomic number stands for the number of protons.
mass number stands for number of neutrons and protons.
30 neutrons + 40 protons = mass number of 70
Hope this helps!
guys help plz I need it
Answer:
may be the answer will be study the structure of the earth and resources.
list 5 chemical properties of water??
Answer:
In the presence of a strong electron donor (strong reducing agent), water serves as an oxidizing agent. In the presence of a strong electron acceptor (strong oxidizing agent), water serves as a reducing agent. On-water reactions are a group of organic reactions that take place as an emulsion in water and have an unusual reaction rate acceleration compared with (i) the same reaction in an organic solvent, or (ii) the corresponding dry media reaction.Amphoteric nature : Water can act as both acid and base, which means that it is amphoteric in nature.Hydrolysis reaction : Water has a very strong hydrating tendency due to its dielectric constant. It dissolves many ionic compounds. Some covalent and ionic compounds can be hydrolyzed in water.Redox reactions : Electropositive elements reduce water to hydrogen molecule. Thus, water is a great source of hydrogen.Mass of a single 35Cl atom
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.
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please help!! will have a thanks and brainliest
Answer:
A
Explanation:
I just did learned all about this
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
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How is a beta particle formed?
Answer:
forms when a neutron changes into a proton and a high-energy electron .
hope this helps <3
9 ml of a sugar solution was mixed with 3 ml of a 76% sugar solution to make a 73% sugar solution. Find the percent concentration of the first solution.
Someone pls help me
Answer:
A. 4 cm, 40 mm
B. 5.5 cm, 50 mm
C. 8.8cm, 80 mm
D. 8.2 cm, 82 mm
E. 9.5cm, 95 mm
Explanation:
NB: 1 cm = 10 mm
Why are some ions known as poly atomic ions?
Answer:
NH4+ ammonium ion hydroxide ion
SO32- sulfite ion perchlorate ion
NO3- nitrate ion chlorate ion
NO2- nitrite ion chlorite ion
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.
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
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Select the correct answer from the drop-down menu.
why did rutherford think that all of the alpha particles would go straight through?
Explain why titritations using permanganate are performed in Acid solutions
The titration using permanganate in acidic solution because it can be act as behave indicator.
What is titration?Titration is a typical quantitative chemical analysis procedure used in laboratories to quantify the concentration of a specified analyte. The titrant or titrator is a substance that is manufactured as a standard solution with a given concentration as well as volume.
Permanganate titrations must be performed in a strong acid solution. Because [tex]HNO_{3}[/tex] and HCl might involve in competing for a redox reaction, lowering the accuracy of the titration, sulfuric acid is commonly utilized. Titration permits food manufacturers to calculate the amount of a reactant present in a sample.
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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.
What will happen when we replace oxygen with nitrogen in our life while breathing and what will happen if it was in our cells? (Theory no one has ever thought)
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
Who was the first to recognize that the observations and experimental results
regarding matter could be explained by the existence of atoms?
a. Grookes
b. Rutherford
c. Ballen
d. Chadwick
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.
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what is the density of a object that has a volume of 8 ml and a mass of 22 grams?
Answer:
The density of the object is 0.32gcm3.
Explanation:
hope this helps
what kind of chemical processes are used to create these synthetic products
Aluminium is a natural material that is widely utilised in a variety of sectors and may be converted into a variety of synthetic goods via various chemical processes.
The following are some examples of synthetic compounds created from aluminium and the accompanying chemical processes:
Aluminium Foil: Aluminium foil is a thin, flexible sheet of metal.Aluminium Cans: Aluminium cans used for beverage packaging are created through a process known as can forming. Aluminium alloys are synthetic goods formed by mixing aluminium with additional elements such as copper, zinc, magnesium, or silicon.Thus, these are only a few examples of synthetic goods generated from aluminium and the chemical processes that produce them.
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Your question seems incomplete, the probable complete question is:
What synthetic products are derived from the natural resource aluminum? What kind of chemical processes are used to create these synthetic products?
The reaction between sodium and water releases a lot of energy to the
surroundings. What type of process is this?
Answer:
an exothermic reaction i think
Explanation:
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.
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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.
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
How does heat affect solubility of solids in a liquid?
A. The particles of a solid lose their shape and do not dissolve properly when heated
B. Solubility is not affected by heat.
C. Solubility generally decreases with heat.
D. Solubility generally increases with heat.
Answer:
Option D
Explanation:
Solubility is the amount of a substance in a solvent that dissolves at a specific temperature. So knowing this you would know that generally when you increase the temperature it also increases the solubility of a substance which means the answer is option D or "Solubility generally increases with heat."
Hope this helps.
Answer:
D.) Solubility generally increases with heat
Explanation:
I got it correct on founders edtell
How many total atoms are in this formula?
2MgSO4
describe the critical processes by which nitrogen is cycled through the biotic and abiotic components of earth’s ecosystems and identify the primary storage sink for nitrogen.
Nitrogen is one of the major elements that are cycled in nature. The major sink for nitrogen in nature is the atmosphere.
Biogeochemical cycles in nature show the diverse ways that elements move through the various spheres on earth.
Nitrogen is trapped from the atmosphere by nitrogen- fixing bacteria that live in the root noodles of leguminous plants which convert atmospheric nitrogen to nitrates. This nitrogen is transferred to living organisms when they eat those plants and become incorporated into biomass.
Decomposition returns this nitrogen in biomass to the soil. The action of denitrifying bacteria converts nitrates in soil back to atmospheric nitrogen. Also several anthropogenic sources release nitrogen into the atmosphere as NOx.
The atmosphere consists of 78% nitrogen hence it serves as the largest sink for nitrogen in nature.
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in which direction on the periodic table does metallic character increase?
Answer:
Metallic character increases down each Group of the Table as the outer electrons are further from the nucleus and require less energy for their removal. (a) metallic character decreases from left to right in each Period.
Explanation:
The metallic character increases down each Group on the periodic table.
The metallic character decreases from left to right in each Period.
What is periodic table ?The chemical elements represents in tabular form.The elements in periodic table arranged on the basis of increasing atomic masses.The interactive periodic table showing name, atomic number, atomic mass, boiling point, melting points , state of matter etc.What is metal and its metallic character?The elements having strong tendency to loss their electrons is called metals.The metals have characteristics of ductile, malleability, The metallic character refers to reactivity of metals.learn about metallic character,
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