1. ₉¹⁹F
2. Mg(OH)₂
3. 2H₂ + O₂ ⇒ 2H₂O
Further explanation1. Fluorine, atomic number : 9 , mass number = 19
Symbol : ₉¹⁹F
protons=electrons=atomic number = 9
neutrons = mass number - atomic mass
[tex]\tt n=19-9=10[/tex]
Configuration : [He] 2s² 2p⁵
2. Magnesium hydroxide is an ionic compound and is a strong base consisting of 2 ions:
Positive ion: Magnesium: Mg²⁺
negative ion: Hydroxide: OH⁻
The charges of the two are crossed, so that the compound becomes:
Mg(OH)₂
3. Reaction :
H₂ + O₂ --------> H₂O
give coefficient :
aH₂ + bO₂ --------> H₂O
H, left = 2a, right 2⇒2a=2⇒a=1
O, left = 2b, right 1⇒2b=1⇒b=0.5
Reaction becomes :
H₂ + 0.5O₂ --------> H₂O x 2
2H₂ + O₂ --------> 2H₂O
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
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........
please help I need to ace this test
When two atoms attach to each other by sharing electrons it is called a...
A: Covalent bond
B: Ionic bond
C: none of these - atoms can't bond to each other.
D: Nuclear bond
2nd question
Two hydrogen atoms bonded together form a compound
A: True
B: False
3rd question
Water is two hydrogen atoms bonded to an oxygen atom. This is an example of a compound
A: True
B: False
like I said I need help on this and I don't wanna fail
#1: A covalent bond
#2 False
#3True
- 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!
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
What type of radioactive decay is shown? 82 Br → 82 Kr + te 35 36 Alpha O Beta O Gamma?
Answer:
In 1889, Ernest Rutherford recognized and named two modes of radioactive decay, showing the occurrence of both processes in a decaying sample of natural uranium and its daughters. Rutherford named these types of radiation based on their penetrating power: heavier alpha and lighter beta radiation. Gamma rays, a third type of radiation, were discovered by P. Villard in 1900 but weren't recognized as electromagnetic radiation until 1914. Since gamma radiation is only the discharge of a high-energy photon from an over-excited nucleus, it does not change the identity of the atom from which it originates and therefore will not be discussed in depth here.
Because nuclear reactions involve the breaking of very powerful intra nuclear bonds, massive amounts of energy can be released. At such high energy levels, the matter can be converted directly to energy according to Einstein's famous Mass-Energy relationship E = mc2. The sum of mass and energy are conserved in nuclear decay. The free energy of any spontaneous reaction must be negative according to thermodynamics (ΔG < 0), and ΔG is essentially equal to the energy change ΔE of nuclear reactions because ΔE is so massive.
Explanation:
Hope it helps
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'sPlease help brainiest is award!
can anyone try my questions, please will give points
Answer:
um..... okay I'll give it a shot
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 method of heat transfer is the person in the picture below most worried about?
Radiation
Conduction
Convection
Answer:
Radiation ...........
[tex]\huge\boxed{Conduction}[/tex]
_____________________________________Conduction:Conduction is the transfer of heat when two things come in contact with each other. The energy transfer is from hotter body to the colder body.
x---------------------------------------------x
Fire Walking:There is a trick behind fire-walking. When the coal burns, after sometime there is a layer of ash on the surface of the coal which blocks the radiation. So the transfer of heat is not possible from radiation. Conduction is the only way possible. The person's feet and coal both are poor conductor of heat so if we walk quickly i.e. there is minimal time of contact with the coal, it will just feel a little warm. As the person start walking on the coal, It has to do it quickly, that way Person will feel its sole warming up but it is not that hot because of the layer of ash and poor conductance, after few steps the ash also sticks on to the sole of the person which makes kind of double layers of ash. So the only way for heat transfer is CONDUCTION.
_____________________________________Best Regards,'Borz'Limestone formations in caves is considered what kind of weathering?
hydraulic
mechanical
biological
chemical
Answer:
chemical
Explanation:
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:
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.
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:
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.
salacties 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.
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:
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:
The metal element cesium has one electron in its outer orbit. Will cesium atoms form positively charged or negatively charged ions? Predict their charge.
Answer:
Caesium atoms will form positively charged ions.
Explanation:
Due to them having one electron in their outer orbit, it is very likely that they will give that electron away to form an octet and become stable. Hence, since they lose an electron, they lose a negative charge, and in comparison to their former non-ion self, they have gained a positive charge.
Hence, they will form positively charged ions.
Hope this helped!
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
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
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.
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:
“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
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.
What determines whether something is a solid, a liquid or a gas?
state two uses of graphite which depends on the above properties
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: