Answer:
The number ''n''of a period on the periodic table is the same as the number of the highest principal energy level for the atoms on that row that is, the principal energy level occupied by its valence electrons. Thus, elements on period 1 have a highest principal energy level of 1, and so on.
Las disoluciones comerciales de HCl (PF = 36.5 g/mol) típicamente son 39.0% P/P de este ácido en agua. Determine la molalidad de la disolución del HCl si la densidad de la misma es igual a 1.20 g/ml.
The translation of the question is
Commercial solutions of HCl (MP = 36.5 g / mol) are typically 39.0% W / W of this acid in water. Determine the molality of the HCl solution if its density is equal to 1.20 g / ml.
Answer:
Molality is 17.51 molal
Explanation:
We are given 39% w/w of HCl, this means for every 100g of this solution we have 39g of HCl in it.
to ease the calculation we assume we have 1L(1000ml) of this solution is present.
Density = mass /volume
1.20 = mass/1000
mass = 1200 g of solution
and we are given that 39% of this solution is will contain HCl
so
1200 * 39/100 = 468g of HCl present
no of moles of HCl = 468/36.5 = 12.82moles
mass of solution = mass of water + mass of acid
mass of water = mass of solution - mass of acid
Mass of water = 1200 - 468 = 732g of water
Molality = moles /masss of water in kg
= 12.82 *1000/732 =17.51molal
A physical change can be distinguished from a chemical change because during a physical change- a. the properties of the substance may change, but no new substances are produced b. the properties of the substance change for only a short time but will return to their original state. c. an entirely new substance with new properties forms as a result of the change d. a new substance is produced, but the new substance has properties identical to the original substance
Answer:
C. an entirely new substance with new properties forms as a result of the change
Answer:
. an entirely new substance with new properties forms as a result of the change
Explanation:
Can someone tell me the answer for this!!!
Answer:
Rutherford predicted that an atom has a dense core called a nucleus.
Explanation:
Ernest Rutherford was a physicist who is known as the father of nuclear physics. He suggested an atomic model known as the Rutherford model. According to him, the atom consists of a tiny, dense, positively charged core called a nucleus and negatively charged particles called electrons that circulate around it The nucleus consists of positively charged particles called protons and neutral particles called neutrons.
Which chemical equation best represents the process of photosynthesis?
Answer:
6CO2 + 6H20 ----> C6H12O6 + 6O2
Explanation:
(Carbon Dioxide) + (Water) ------> (Glucose) + (Oxygen)
Answer:
A
Explanation:
CO2= carbon dioxide
H2O= water
C6H12O6=glucose
O2=oxygen
state two uses of graphite which depends on the above properties
5. Flash floods occur when water collects at a faster rate than the water can be absorbed into the surrounding soil. During a lab investigation, students test water absorption rates for four types of soil, including clay, gravel, loam, and sand. The results from one experiment are provided in the table below. Soil Type Water Absorption Rate for 1L of Water (s) Clay 210 Gravel 45 Loam 180 Sand 60 Based on the data provided, which soil type is most likely to experience a flash flood? help me !!!!!!!!
Answer:
clay
Explanation:
its more than the rest
What does the chemical formula CaCl2 show about the compound it represents?
A.It is made up of one element.
B.It is made up of two elements.
C.It is made up of three elements.
D. It is made up of four elements.
Help asap please
Answer:
b
Explanation:
What is radioisotope?
Answer:
An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable. Radioisotopes may occur in nature or be made in a laboratory. In medicine, they are used in imaging tests and in treatment.
Hope I could help!
Answer:
(RAY-dee-oh-I-suh-tope) An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable. Radioisotopes may occur in nature or be made in a laboratory. In medicine, they are used in imaging tests and in treatment. Also called radionuclide.
Explanation:
“Different periods in human history are named for the materials used to make tools. Dr. Franklin is searching through layers of soil, looking for tools made by humans. After screening the top layer of soil, he uses a magnet to help speed up the search.”
Which type of location is Dr. Franklin most likely searching?
A) a cave from before the Stone Age
B) a Stone Age cave
C) a Bronze Age battle site
D) an Iron Age farm
Answer:
Iron age farm
Explanation:
edge 2020
Answer:
D
Explanation:
Got it right on edge
A group hikes from sea level to a mountain peak. Each letter in the diagram indicates a spot where the group stops to drinks boiling water. At Wich point in the hike does water have the highest point.
Answer:
oh my god i have learnt about this
Explanation:
Answer:
Point A
Explanation:
I dont know why but it was right on the test.
Which of the following is a physical change?
Sugar dissolving in water
Milk souring
Metal rusting
Paper burning in a fire
Answer:
sugar dissolving in water
Explanation:
at the end mixing 2 substances and not get a new substance is not a chemical change. the sugar is still sugar even when its in water.
What a higher or lower temperature make particles in a substance move faster
Answer/Explanation:
A higher temperature causes the molecules in a substance to move faster in a chemical change. This increased speed allows the particles to have enough force for a chemical change and it also increases the amount of times a particle hits another this makes it faster for it to combine.
Limestone formations in caves is considered what kind of weathering?
hydraulic
mechanical
biological
chemical
Answer:
chemical
Explanation:
The mass of an object is 32g and its density is 17g /mL. what is its volume
Explanation:
here,
Mass (m)= 32 g =0.32 kg
Density(d)= 17 g/ml
volume (v)=?
we know that,
d=m/v
17=0.32/v
v= 0.32/17
v=0.018
Answer:
[tex]\boxed {\boxed {\sf v \approx 1.88 \ mL}}[/tex]
Explanation:
The density formula is:
[tex]d=\frac{m}{v}[/tex]
If we rearrange the formula for volume, the result is:
[tex]v=\frac{m}{d}[/tex]
The mass of the object is 32 grams. The density is 17 grams per milliliter.
[tex]m= 32 \ g\\d= 17 \ g/mL[/tex]
Substitute the values into the formula.
[tex]v=\frac{32 \ g}{17 \ g/mL}[/tex]
Divide. Note that the grams, or g, will cancel each other out.
[tex]v=\frac{32 }{17 \ mL}[/tex]
[tex]v=1.88235294 \ mL[/tex]
Let's round to the nearest hundredth to make the answer more concise.
The 2 in the thousandth place tells us to leave the hundredth place as is.
[tex]v \approx 1.88 \ mL[/tex]
The volume of the object is about 1.88 milliliters.
what is the
difference between ice
and water vapour.
Answer:
Nothing. I guess ice vapor is a solid and water vapor is a liquid if nothing isn't an option, but that makes no sense.
Explanation:
Write the electron configuration for the electrons identified by the following quantum numbers:
a) 2, 1, 0, -½
b) 4, 2, 0, -½
c) 5, 3, 2, -½
Thanks!
Answer:
see the answer at the pic
The electron configuration for the electrons as listed are:
a) 1s² 2s² 2p⁵ = 9X
b) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁸ = 46 X
c) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴
Using the quantum numbers of the identified electrons to derive the electron configuration ( the representation of the distribution of electrons in the orbit of an atom ) electron configuration of electrons can be calculated using the formula :2n².
where n = orbit number and the various energy levels are represented as 1,2,3,4... while shells of the an atom is written as K,L,M,N
hence the electron configuration of the electrons identified by the quantum numbers are as written above.
Learn more : https://brainly.com/question/20974986
What are the advantages of an electromagnet? PLEASE ANSWER!!
Answer:
The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field
What is the relationship between the number of energy levels that an electron falls and the energy of the photon that is emitted when it falls?
Answer:
Hope this helps! :)
Explanation:
Light is absorbed when an electron jumps to a higher energy orbit and emitted when an electron falls into a lower energy orbit. The energy of the light emitted or absorbed is exactly equal to the difference between the energies of the orbits.
The energy of the electron drops when it changes levels, and the atom releases photons. The emission of the photon occurs as the electron transitions from a higher to a lower energy state.
What is a photon ?The electromagnetic force is carried by a photon, a basic particle that is a quantum of the electromagnetic field and includes electromagnetic radiation like light and radio waves. Since photons have no mass, they constantly travel in a vacuum at the speed of light.
When a photon of the appropriate wavelength collides with an atom, it vanishes and transfers all of its energy to the electron, which causes it to jump to a higher energy level.
The energy differential between two energy levels determines the amount of energy that is released during a certain transition.
Thus, The energy of the photon is precisely the energy that is lost when an electron moves to a level with less energy.
To learn more about photon, follow the link;
https://brainly.com/question/28134171
#SPJ2
In order to follow the octet rule, how many valence electrons do most elements
want?
a. 2
b. 4
c. 6
d. 8
Answer: D (8)
Explanation:
Answer:
d. 8
Explanation:
The octet rule refers to the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds.
4 Describe What effect does observing a
substance's physical properties have on the
substance?
Answer:
From observing a substance's physical properties it has no effect on the substance because you are just observing it and not changing it.
8. Consider the element Scandium, atomic # 21.
(a) If the electronic configuration of the element were constructed "from scratch", into which
orbital (and into which shell) would the final electron be placed? (1)
(b) When scandium forms an ion with a charge of +1, from which orbital (and from which
shell) would the electron be removed? (1)
Explanation:
Scandium has atomic number of 21. This means that in it's neutral state its going to have 21 electrons.
a) The full electronic configuration is given as;
1s2 2s2 2p6 3s2 3p6 3d1 4s2
The final electron is placed in the d orbital. The shell is 3d
(b) When scandium has a charge if +1, it has lost an electron. The total number of electrons would now be 21-1 = 20
The electronic configuration would be given as;
1s2 2s2 2p6 3s2 3p6 4s2
The electron in the 3d orbital would be removed.
Niels Bohr’s model of the atom helped to explain
Answer:
a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits.
Explanation:
When propane is reacted in the presence of oxygen gas, the products of this combustion reaction are: A. CO + H2O B. CO2 + H2O C. C2H4 + H2O D. CH4 + H2O
Answer:
B. CO2 + H2O
Explanation:
Propane is an hydrocarbon as it contains only v=carbon and hydrogen atoms.
Whenever an hydrocarbon reacts with oxygen or undergoes a combustion reaction, two products are always formed only,
These two products are;
Carbon dioxide (CO2) and water (H2O)
This means the correct option is option B.
Which one is non polar covalent Bond 1) H2, O2, HCL. 2)K, Fe, Ca or 3)N2, H2, Cl2
Answer:
3)N2, H2, Cl2........
Calculate a sm for the equation below. (Round to the nearest whole number.) 4NH, (g) +50, (g) → 4NO(g) + 6H2O(g) = 192.8 J/mol K SH = 205.0 J/mol K S. SHO = 188.83 J/mol K So = 210.8 J/mol K AS JIK
Answer:
the answer is 180 j/k i think
Explanation:
Answer: its 79 for the first part and 180 on the second part
Explanation:
Please help brainiest is award!
- All the metals of group 1 react with water, liberating hydrogen gas and forming metal
hydroxides. Suppose you are provided with a piece of metal stored in a bottle labelled as
‘Rubidium’. Based on your knowledge of the periodic table explain why it is not safe to
dispose it in sink with water?
Answer:
since it is in grp 1, it will react with water like all other metals.
Answer:
Rubidium, as a Group 1 metal, will have a strong reaction with the water and form hydrogen. The reaction is so strong it might even be explosive, hence the danger of putting it in water.
Explanation:
Hope this helped!
Hurry Find the slope for the liner relation described in the table
Answer:
2.75
Explanation:
For every ride taken the money spent goes up by $2.75.
Balance the equation Mg+CO2 - - - - - -) MgO+c
Answer:
2Mg (s) + CO₂ (g) → 2MgO (s) + C (s)
General Formulas and Concepts:
Chemistry - Reactions
Reaction PredictionBalancing RxN'sExplanation:
Step 1: Define RxN
Mg (s) + CO₂ (g) → MgO (s) + C (s)
Step 2: Balance RxN
2Mg (s) + CO₂ (g) → 2MgO (s) + C (s)
We need to balance the number of O's on both sidesIf we balance the O's, we will also need to balance the Mg'ssalacties and stalagmites are formed in a cave due to deposition of carbonates when temporary hard water evaporates, please help me I will mark u brainlist true or false
The answer is True because they are formed of deposition.