Answer:
group 18
Explanation:
Elements with the most valence electrons are in group 18
chemical properties of sodium
Answer:
Density 0.97 g.cm -3 at 20 °C
Melting point 97.5 °C
Boiling point 883 °C
oxidation states +1, −1 (rare)
Explanation:
Have a nice day
Calculate the normality of a solution made by diluting 12 g of H3PO4 with water to produce 250.0 mL of solution.
The normality of a solution made by diluting 12 g of H3PO4 with water to produce 250.0 mL of solution is 1.47 eq/L.
The normality of a solution is;
N = Mass of solute in grams/volume of solution in litres × Equivalent weight
Mass of solute = 12 g
volume of solution = 250.0 mL or 0.25 L
Equivalent weight = Molar mass of H3PO4/n
n = Number of hydrogen ions in H3PO4
Equivalent weight = 98 g/mol/3 = 32.7
Substituting values;
N = 12/0.25 × 32.7
N = 1.47 eq/L
Learn more: https://brainly.com/question/2510654
how long does it take cream cheese to get to room temperature?
Since cream cheese has such a high fat content, it doesn't take long to come to room temperature if the room is relatively warm. It takes about thirty minutes on the counter to soften significantly, and about an hour to fully come to room temperature again, depending on the temperature outside and in your kitchen
HELP!!!!
four different liquid compounds in flasks at 20 C are represented above. the table below identifies the compounds. flask c shows the most particles in the vapor phase. which of the following is not shown in the model but best helps to explain why flask c must contain pentane
Answer: C , The strength of the intermolecular forces between the particles in the liquids.
Explanation:
Since we have 4 boiling flasks with liquids that are at a temp of 20⁰C and out of them all, flask C the has most amount of vapour Particles inside of it, because of that we can conclude that it has the weakest Intermolecular force out of the rest of the boiling flasks since at a temp of 20⁰C it has the most amount of gas particles compared with the other flasks, and not to forget the data in the graph shows us the formula and boiling point of flask C that contains pentane and from that data given we can tell that since the boiling point of pentane Is low then it has to have a weak intermolecular forces, causing it to have more vapour Particles than other flasks, proving the answer to be C since showing the strength of the attraction will explain everything we need to know about flask C and why does it have more vapour Particles than the other flasks.
Note:
(A) is not the answer since all the liquid particles in each flask are in random constant motion at a temp of 20⁰C so it does not justify why flask C has more vapour Particles.
(B) is not the answer since showing the relative speeds of each vapour Particle will not justify why flask C has the most amount of gas particles with the respect of its temperature.
(D) is not the correct answer since we already have data given in the graph about the boiling point of pentane and it's formula so showing the particulate representation is useless.
The best explanation is the strength of intermolecular force between the particles in a liquid. Thus option C is correct.
What is intermolecular force?Intermolecular force is defined as the attractive and repulsive force that rises between the molecules of a compound. They are electrostatic in nature.
There are basically five type of intermolecular force.
Dipole-Dipole interactionIon Dipole interactionIon induced dipole interactionDipole induced dipole interactionDispersion forceThe first three forces are collectively known as Vander wall force.
Thus, the best explanation is the strength of intermolecular force between the particles in a liquid. Thus option C is correct.
To learn more about intermolecular force, refer to the link below:
https://brainly.com/question/9328418
#SPJ2
How do you know how to order an empirical formula?
Answer:
Start with the number of grams of each element, given in the problem. the mass of each element = the percent given. Convert the mass of each element to moles using the molar mass from the periodic table. Divide each mole value by the smallest number of moles calculated.
How many molecules are there in 3.1 mol CO2
Answer:
Abs : 1.8662 × 10^24
Explanation:
1 mol of CO2 contains 6.02 × 10^24 molecules
So, 3.1 mol of CO2 contains 6.02 × 10^24 × 3.1 mol = 1.8662 × 10^24
how many core electrons are there in a sodium atom?
Answer:
There are 13 core electrons in a sodium atom.
what is an electron ?state it's relatively mass and charges.
Answer:
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
mass: 9.1093837015 × 10−31 kg
charges: fundamental physical constant expressing the naturally occurring unit of electric charge, equal to 1.602176634 × 10−19 coulomb.
Explanation:
good luck !<3
What is the change in oxidation number of bromine in the following re-dox reaction Cl 2 +2HBr 2HCl+Br 2 A -2;0 B) -1;0 C) 0: -1 D) 0;-2
Answer:
ANSWER
ANSWER: +1
EXPLANATION
What is the change in oxidation number of bromine in the following re-dox reaction Cl 2 +2HBr 2HCl+Br 2 A -2;0 B) -1;0 C) 0: -1 D) 0;-2
for Cl 2 +2HBr 2HCl+Br 2 , the Cl in Cl2 is reduced from "0" to
"-1" and the Br in HBr is oxidized from "-1" to "0"
So the change in oxidation number is +1
A compound is 2. 00% H by mass, 32. 7% S by mass, and 65. 3% O by mass. What is its empirical formula? The third step is to calculate the mole ratios of the elements present. To do this, you will divide each molar amount by the smallest molar amount. The molar amounts of the elements present are:.
Samantha is investigating the densities of several liquids. Which action is the result of her creative thinking ?
Answer:
A. Poe
Explanation:
pagmali sorry na Lang
if the column of water in the water barometer rose to a height of 39 feet, what would the atmospheric pressure be in mm hg?
The atmospheric pressure for a column of water barometer that rose to 39 feet is 874 mmHg
From the given information, to determine the atmospheric pressure at which the column of the water barometer rose, we will need to convert the height of the water column to mmHg.
From the dimensional analysis of standard rate conversion, we know that:
1 feet = 12 inches
1 inch = 25.4 mm
1 mmHg = 13.6 mm of water.
∴
[tex]\mathbf{\implies 39 \ feet \ of \ H_2O \times \dfrac{12 \ in ch \ H_2O}{1 \ feet \ H_2O} \times \dfrac{25.4 \ mm \ H_2O}{1 \ inch \ H_2O} \times \dfrac{1 mmHg}{13.6 \ mm \ H_2O}}[/tex]
= 874.058 mmHg
Learn more about conversion ratio here:
https://brainly.com/question/15398863?referrer=searchResults
How many electrons are there in the N shell of an element?
[tex] \huge \mathbb \pink{ANSWER:}[/tex]
2,5 the elctrons arw there in the N shell of an element.Explanation:
Hope it helps ^•^
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons
Transition metals have roman numerals after the metal name
t or f ??
Answer: false
Although they bel,ong to the transition metal category, these metals do not have Roman numerals written after their names because these metals only exist in one ion.
...
What are the component of science?
What are the descriptions?
How does it form?
Hope you can answer properly
^_^ ❤☺
[tex] \large \text{Answer} \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ [/tex]
1.ans: observations, questions, hypothesis, methods and results are the five components of scientific method.
2.ans: written account of object.
3.ans: sry I didn't get
hope my 2 answers can help you ࿐❤
Answer:
1) Sience involves six kinds of components:
• Problems
• Attitudes
• Methods
• Activities
• Conclusions
• Effects
2) Knowledge is information or information that is known or realized by someone.
3) Science form:
• Direct knowledge (direct)
• Indirect knowledge (mediated)
• Sensory knowledge (perception)
• Conceptual knowledge (conceptual)
• Particular knowledge (special)
• Universal knowledge (universal)
Explanation:
I hope this help :)
Proteins have two main secondary structures: _______, which are spirals formed by hydrogen bonds between amino acids, and _______, which are formed by a bend in the amino acid with alternating hydrogen bonding between amino acids.
Answer:
Explanation:
Proteins have two main secondary structures: alpha helices, which are spirals formed by hydrogen bonds between amino acids, and beta pleated sheets, [ which are formed by a bend in the amino acid with alternating hydrogen bonding between amino acids.
Elabore el balance de la ecuación por oxido reducción enumerando cada paso
CaC2O4 + KMnO4 + H2SO4 → CaSO4 + MnSO4 + K2SO4 + CO2 + H2O
Answer:
[tex]{ \rm{5CaC _{2}O _{4(aq)}+ 2KMnO _{4(aq)} + 8H _{2} SO _{4(aq)} → 5CaSO _{4(s)}+ 2Mn SO _{4(aq)}+ K _{2} SO _{4(s)} + 10CO _{2(g)} + 8H _{2} O _{l} }}[/tex]
Explanation:
This is a redox reaction formed by combining two half equations.
Check the image above, sorry if my handwriting is poor :(
The
( )state is the lowest possible energy level that an electron can occupy.
When the electron gains energy, it may move to a higher energy level. This is called the( )
state
Answer: ground state
Explanation: The ground state, assuming you’re talking about an electron in an atom. As far as isolated leptons go, the electron is the lowest energy among the electron, muon, and tau particles. Muons and tau particles are unstable. A tau can decay into a muon or electron or other decays, while a muon can decay into an electron and associated neutrinos or gamma rays. Each has a corresponding neutrino, all of which have really, really tiny masses. P.S not copy pasted
Ground state is the lowest possible energy level that an electron can occupy. When the electron gains energy, it may move to a higher energy level. This is called the exited state.
The ground state is the lowest possible energy level that an electron can occupy within an atom. In this state, an electron is in its most stable configuration, meaning it is closest to the nucleus and has the lowest energy level available to it.
When an electron gains energy from an external source, such as absorbing a photon of light or heat, it can move to a higher energy level. This state is known as the excited state. In the excited state, the electron is located farther from the nucleus and possesses more energy than it does in the ground state. The additional energy is stored by the electron as potential energy in its increased distance from the nucleus.
The excited state is temporary. Electrons in an excited state are not stable, and they tend to return to lower energy levels (closer to the nucleus) by releasing the excess energy in the form of photons of light. This phenomenon is the basis for various processes, including fluorescence and emission spectra.
To learn more about atom
brainly.com/question/1566330
#SPJ3
what is the number of electrons in a potassium atom
Answer:
19 electrons, that's what I say
What was the effect of decreasing the copper's mass?
Answer:
Decreasing the temperature of the copper made the final temperature decrease.
Heat emitted by copper reduces as copper's mass decreases. As the mass of copper lowers due to a decrease in heat gain by water, the final temperature also drops.
What is heat?The transfer of kinetic energy from an energy source to a medium, an object, or from one to the other is referred to as the creation of heat. The sun is the source of all energies. It is the natural source of solar energy, heat, and light. Thermal energy can move through three different channels: conduction, convection, and radiation.
Therefore, the increase in temperature is always proportionate to the mass of water. Thus, the final temperature will be lower if we increase the water mass. The temperature will be lower in the end. The density reduces as volume grows. Consequently, density drops as temperature rises.
Thus, heat emitted by copper reduces as copper's mass decreases. As the mass of copper lowers due to a decrease in heat gain by water, the final temperature also drops.
To learn more about heat, refer to the link below:
https://brainly.com/question/1429452
#SPJ2
What does displacement reaction tell you about the reactivity of the 2 metals involved?
it tells me that one element is more reactive than the other
Explanation:
using the reactivity series. the element that come above is the most reactive e.g
potassium
sodium
calcium
magnesium....
potassium is more reactive than sodium and the following below
calcium is more reactive than magnesium since it is below it in the reactivity series.
CONCLUSION, reactivity decreases down the reactivity series and increases up the reactivity series. the example i gave is part of the reactivity series of cations but there is also for anions
1) A book is pushed and released and it slides across a table for a short distance The book quickly comes to a stop. The book originally has kinetic energy. To what for at
energy is the kinetic energy transformed?
A) The kinetic energy is transformed into heat
B) The kinetic energy is transformed into chemical energy
C) The kinetic energy is not transformed into any other type of energy
D) The kinetic energy is transformed into electrical energy
Answer: A the kinetic energy is transformed into heat
Explanation:
A solid magnesium flare has a mass of 1300 g and a volume of 743 cm3. What is the density of the magnesium?
Answer:
1.74 g/cm3
Explanation:
density=mass/volume
Explanation:
density = 1300/743
or density=1.74g/cm3
How does an electric generator work?
Answer:
A conductor coil (a copper coil tightly wound onto a metal core) is rotated rapidly between the poles of a horseshoe type magnet. ... The magnetic field will interfere with the electrons in the conductor to induce a flow of electric current inside it.
How many elements are in the other metals group
Answer:
7 elements
Explanation:
Answer:
There are 7 elements
Explanation:
Determine the rate of reaction at 50 C when the loss of mass is 0.95 g. Show your working. Give your answer to 2 significant figures.
* 20 points for who gets it *
This problem is providing information about the loss of mass for a reaction 50 °C as a function of the time elapse. Thus, when taking a look at the given graph, we can trace a horizontal line on the y-axis at 0.95 g in order to intercept it with the curve, and hence, figure out the time at which that loss of mass takes place.
Thus, we can see that when the loss of mass hits 0.95 g, the corresponding time on the graph is about 80 seconds, and hence, the rate of reaction turns out to be:
[tex]r=\frac{0.95g}{80s}\\\\r=0.012\frac{g}{s}[/tex]
Which has two significant figures as required.
Learn more:
https://brainly.com/question/24072508 https://brainly.com/question/8983899why would someone need to find the relative density of an object?
Answer:
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it's in will sink. An object that has a lower density than the liquid it's in will float.
Explanation:
Hope it helps!
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it's in will sink. An object that has a lower density than the liquid it's in will float.
This principle is fundamental to understanding why objects float or sink in fluids and are commonly observed in everyday situations. For example, ships and boats float on water due to their design and the distribution of weight, while heavy materials like metal sink in water because their density is greater than that of water.
Therefore, The concept of relative densities and buoyancy has significant applications in various fields, including shipbuilding, architecture, swimming, and understanding the behavior of objects in liquids.
To know more about the density:
https://brainly.com/question/29775886
#SPJ3
How many cobalt atoms are in 2 moles of cobalt?
That means that one mole of cobalt weighs 58.9332 grams (58.9332 g/mol). Based on that information, to convert 2 moles of cobalt to grams, we multiply 2 moles of cobalt by 58.9332.
12.04428152 x [tex]10^{23}[/tex] cobalt atoms are in 2 moles of cobalt.
What are moles?A mole is defined as 6.02214076 ×[tex]10^{23}[/tex]
of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
One mole of cobalt is equal to 6.02214076 ×[tex]10^{23}[/tex] atoms.
2 moles of cobalt is equal to 6.02214076 × [tex]10^{23}[/tex]atoms x 2
12.04428152 x [tex]10^{23}[/tex]
Hence, 12.04428152 x [tex]10^{23}[/tex]cobalt atoms are in 2 moles of cobalt.
Learn more about moles here:
brainly.com/question/8455949
#SPJ2
Question 1 (2 points)
Which option can be classified as a pure substance?
Question 1 options:
heterogenous mixture
solution
homogenous mixture
compound
Question 2 (2 points)
Law of conservation of mass states that:
Question 2 options:
matter is destroyed
matter does not change
matter is neither created nor destroyed
matter is created
Question 3 (2 points)
What is a property of bases?
Question 3 options:
all of the above
Sour taste
Slippery touch
Ability to form hydronium ions+
Question 4 (2 points)
Which property do solutions with low pH values have?
What does it mean to have a neutral pH? - Aseptic Health
Question 4 options:
have a -OH group
feels slippery
turns litmus paper blue
tastes sour
Question 5 (2 points)
How do the products of chemical reactions compare to their reactants?
Question 5 options:
The products often have completely different properties than the reactants.
The products are usually more toxic than the reactants.
The products usuallyhave more mass than the reactants.
The products usually have more atoms than the reactants.
Question 6 (2 points)
Which of the following is an example of a physical change?
Question 6 options:
Water freezing into ice.
A piece of wood burning.
A toy car rusting.
Zinc producing hydrogen gas when mixed with water.
Question 7 (2 points)
What might happen if you mixed a strong acid with an equally strong base?
Question 7 options:
You would see an explosive chemical reaction.
The base would destroy the acid.
You'd wind up with a pH-neutral salt and water.
The acid would destroy the base.
Question 8 (2 points)
In the equation shown, what are the reactants?
2H2+O2àH2O
Question 8 options:
Hydrogen and oxygen molecules (2H2 and O2 )
Ice crystals
Hydrogen atoms (H)
Water molecules (H2O)
Question 9 (2 points)
Which phrase most accurately describes a chemical change?
Question 9 options:
A change in form
A change in taste
A change on the molecular level
A change in appearance
Question 10 (2 points)
What does it mean when there is a physical change?
Question 10 options:
A new substance has been formed.
Matter has changed from one substance into a new substance.
Matter has changed size, shape or form
Matter has changed on the molecular level.
help pls ill give 20 points!
Answer:
1) Compound
2) Matter is neither created nor destroyed
3) All of the above
4) Turns litmus paper blue
5) The products often have completely different properties than the reactants.
6) Water freezing into ice
7) You'd wind up with a pH-neutral salt and water.
8) Hydrogen and oxygen molecules (2H2 and O2 )
9) A change on the molecular level
10) Matter has changed size, shape or form
Answer:
compoundmatter is neither created nor destroyedSlippery touchtastes sourThe products often have completely different properties than the reactants. Water freezing into ice. You'd wind up with a pH-neutral salt and water. Hydrogen and oxygen molecules (2H2 and O2 ) A change on the molecular level Matter has changed size, shape or formExplanation:
How long does it take far Uranus to complete one revolution (orbit) around the sun?