Answer:
1. B
2. C
3. C
4. B
Explanation:
1. An atom of sulfur has an atomic number of 16. It has three electron shells and six valence electrons, therefore, it belongs to period 3, group VIA of the periodic table
2. Bromine has an atomic number of 35. It belongs to period 4 group VIIA of the periodic table. Therefore, it has four electron shells and seven valence electrons.
3. Argon has an atomic number of 18. It belongs to period 3, group IVA of the periodic table. Therefore, it has three electron shells and eight valence electrons.
4. The Lewis dot model use structures that represent the valence electrons of atoms within a molecule existing as lone pairs or when involved in bonding. They can be used to draw electrons that are involved in a collision during a chemical reaction.
Can someone Help pls :)
Answer:
D. I think
Explanation:
Different isotopes are matched with their uses as (i) Co- 60- To treat cancer (ii) U- 238- To produce electricity (iii) I-131- To treat goitre (iv) Na- 24- In agricultural research Which of the below matches are correct? (i) and (ii) (ii) and (iii) (iii) and (iv) (i) and (iii)
Answer:
I-131- To treat goitre
U- 238- To produce electricity
(ii) (ii) and (iii)
Explanation:
Radioisotopes have various applications in science. These applications may be positive or negative.
I-131- is used to treat goitre. This is a very important medical application of this isotope of iodine.
U-238 is ordinarily non-fissile but can be transformed to Pu-239 and used as a nuclear fuel for electricity generation.
PLEASE HELP IM GOING TO GIVE BRAINLY AND A LOT OF POINTS
Answer:
1)
a- 0.10 mol
b- 0.078 mol
c- 5454.54 mol
d- 0.160 mol
e- 0.022 mol
2)
a) 3.6 g
b) 14.9 g
c) 5.6 g
d) 39.9 kg
e) 6.8 g
3)
a) 28
b) 40
c) 160
d) 28
e) 249.6
Help with questions 9,10,11
Answer:
B
A
C
Explanation:
Need help!!!!!!!!!!!!!
Answer:
density
Explanation:
How many molecules are in 1200 g of acrylonitrile (C3H3N), a chemical used in the production of plastic
Help
Answer: [tex]136.2\times 10^{23}[/tex] molecules
Explanation:
According to avogadro's law, 1 mole of every substance contains avogadro's number of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=\frac{1200g}{53.06g/mol}=22.62moles[/tex]
1 mole of acrylonitrile has = [tex]6.023\times 10^{23}[/tex] molecules
Thus 22.62 moles of acrylonitrile has = [tex]\frac{6.023\times 10^{23}}{1}\times 22.62=136.2\times 10^{23}[/tex] molecules
Taking into account the definition of Avogadro's number, 1.36×10²⁵ molecules of C₃H₃N are in 1200 g.
Avogadro's NumberAvogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.
Mass molarThe molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.
The molar mass of a compound (also called Mass or Molecular Weight) is the sum of the molar mass of the elements that form it (whose value is found in the periodic table) multiplied by the number of times they appear in the compound.
This caseIn this case, you know the molar mass of the elements is:
C= 12 g/moleN= 14 g/moleH= 1 g/moleSo, the molar mass of the compound C₃H₃N is calculated as:
C₃H₃N= 3× 12 g/mole + 3× 1 g/mole + 14 g/mole
Solving:
C₃H₃N= 53 g/mole
You have 1200 g of C₃H₃N. So, knowing its molar mass, you can calculate the number of moles that contain a mass of 1200 g as:
1200 g×[tex]\frac{1 mole}{53 grams} [/tex]= 22.64 moles
Then you can apply the following rule of three: If by definition of Avogadro's number 1 mole of C₃H₃N contains 6.023×10²³ molecules, 22.64 moles of C₃H₃N contains how many molecules?
amount of molecules of C₃H₃N= (22.64 moles × 6.023×10²³ molecules)÷ 1 mole
amount of molecules of C₃H₃N= 1.36×10²⁵ molecules
Finally, 1.36×10²⁵ molecules of C₃H₃N are in 1200 g.
Learn more about
Avogadro's Number:brainly.com/question/11907018?referrer=searchResultsbrainly.com/question/1445383?referrer=searchResultsbrainly.com/question/1528951?referrer=searchResultsMolar mass:brainly.com/question/12695086?referrer=searchResults(Science)The low pressure area near Earth’s equator is filled by cool air moving in from ________.
A
Europe and South America
B
the North and South Pole
C
the Prime Meridian
D
the Atlantic and Pacific Ocean
Answer:
B . the North and South Pole
Explanation:
The equator is also called the doldrum or the region of calms here the winds are moving slowly and consist of warmth and moisture. Thus developing a low-pressure system. Due to which the cool and dense winds that blow from the poles reach the equator and the warm winds move towards the poles balancing the temperatures in both the regions. As these regions don't receive most of the sunlight they have high-pressure cells.how many protons does Beryllium have?
Answer:
4
Explanation:
its a rare element, usually occurring as a product of the spallation of larger nuclei that have collided with cosmic rays
How many significant figures does 0.062400 have?
what is the anwser to this question
Answer:
The answer is d
Explanation:
Answer:
Nitrogen makes up most of the Earth's atmosphere
Explanation:
What are the three main compositional layers of the Earth
Answer:
The Earth is divided into three chemical layers: the Core [Inner Core (D) and Outer Core (C)], the Mantle (B) and the Crust (A).
Explanation:
Which type of reaction always has an element and a compound as reactants?
Group of answer choices
A. decomposition
B. single-replacement
C. double-replacement
Answer:
B. single-replacement
Explanation:
What is a biotic factor
Answer:
can be described as any living component that affects another organism or shapes the ecosystem.
Explanation:
define the term osmosis in your OWN words
Answer:
Osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one equalizing the concentrations on each side of the membrane.
Explanation:
help me id.k this. this is so hard...
Answer:
it's 2:1
ask me if you want explaination also. it is just an mcq that's why i am not giving
thank you
The gas could be which of the following? Select all that apply. Hint: These gases are more dense than air. Nitrogen Neon Argon Carbon Dioxide Helium Hydrogen Propane Carbon Monoxide
Answer:
nitrogen, oxygen, carbon dioxide, argon, hydrogen, helium
Explanation:
Mechanical advantage = load/_______
Answer:
Mechanical advantage = load/effort
Explanation:
Mechanical advantage is like a ratio of load to effort and many machines like pulleys depend on this relationship between load and effort for it to work.
Answer:
The formula of mechanical advantage is Load÷effort
Explanation:
Mechanical advantage is the ratio of the load to the effort i.e. MA=Load(L)÷Effort(E)
Please answer correctly !!!!!!!!!!!! Will mark Brianliest !!!!!!!!!!!!!!!!!!!!
Answer: smart guess i have is c
Explanation:
guessing sorry
Above which temperature does the thermal conductivity of water start to fall?
Answer:
It’s actually 130 degrees Celsius.
Explanation:
Match the intermolecular force with the physical property that will result
Answer:
Intermolecular forces are the forces that bind two molecules together. Physical properties are affected by the strength of intermolecular forces. Melting, boiling, and freezing points increase as intermolecular forces increase. Vapor pressure decreases as intermolecular forces increase. Hope this is what your looking for!
Explanation:
Brainliest please?
. Which laboratory equipment would most likely be used for testing a substance for the presence of monosaccharides? *
Answer:
Benedict's reagent is the indicator we use to detect monosaccharides. When monosaccharides are mixed with Benedict's and heated, a color ange occurs.
Hope this helps!! :)
Using the model of the periodic table, which two elements pictured have similar chemical properties?
Answer:
1 and 3
Explanation:
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
2. Balance the following equations. If an equation is already balanced, say so in
your answer.
a. Cl2 + Br → Cl + Br2
b. CaO + H20 + Ca(OH)2
C. Na2SO4 + BaCl2 → BaSO4 + NaCl
d. ZnS + 02 → ZnO + SO2
e. Cl2 + KBr → KCl + Br2
f. H2SO4 + NaOH → Na2SO4 + H20
BRAINLIEST BRAINLIEST
Please answer
A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have?
13
5
9
4
Answer:
It has 5 neutrons
Explanation:
The fact that it is a neutral atom tells us that the number of electrons and protons is the same:
The problem tells us there are 4 electrons, thus there are 4 protons.The average mass of an atom is the sum of the number of protons and the number of neutrons:
Mass = # Protons + # NeutronsWith the above information in mind we can calculate the number of neutrons:
9 amu = 4 Protons + # Neutrons# Neurons = 5 NeutronsWhat is the chemical formula for zinc (II) phosphate?
Answer:
Zn^3(PO4)2
Explanation:
thats the formula
The chemical formula for compound zinc (II) phosphate is Zn₃(PO₄)₂.
Zinc (II) phosphate is an inorganic chemical compound that is made up of zinc cations and phosphate anions .The chemical formula for zinc (II) phosphate is obtained by combining three zinc cations with two phosphate anions to achieve the neutral charge.
Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
Thus, chemical formula for compound zinc (II) phosphate is Zn₃(PO₄)₂.
Learn more about chemical formula,here:
https://brainly.com/question/32018188
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in which of the following is the symbol for the ion and the number of electrons it contains given correctly? *
Answer:Number of electrons that are present in an atom is determined by the electronic configuration of that atom.
If an ion is carrying a positive charge, it means that the atom has lost electrons and if an ion is carrying a negative charge, it means that the atom has gained electrons.
For the given options:
Option A: The atomic number of hydrogen atom is 1 and the electronic configuration for ion will be:
Thus, this atom does not have any electrons.
Option B: The atomic number of bromine atom is 35 and the electronic configuration for ion will be:
Thus, this atom has 36 electrons.
Option C: The atomic number of aluminium atom is 13 and the electronic configuration for ion will be:
Explanation:
Chromium, cobalt, and manganese are three extremely important metals. Are these metals uniformly distributed in the lithosphere? If not, what region of the Earth is the source of these metals?
Answer:
No.
Explanation:
No, these metals are not uniformly distributed in the lithosphere, they are present some special regions of earth. Chromium ore is found in many places including South Africa, India, Kazakhstan and Turkey. Cobalt ore deposits are present in the regions of Congo, Canada, Australia, Zambia and Brazil. China, Africa, Australia and Gabon are the regions on the earth where manganese metal is present in large quantity.
What is the molar mass of the anhydrous compound? Answer using four significant figures.
36.02 g/mol
120.15 g/mol
156.12 g/mol
Answer:
120.15
Explanation:
ta edg
Answer:
120.15
Explanation:
edg 2021
Consider the reaction
H,01) +energy > H2(g) +%02(g)
Which of the following phrases best describes this reaction?
A Endothermic, absorbing energy
B) Endothermic, releasing energy
C) Exothermic, absorbing energy
D) Exothermic, releasing energy
The following phrases best describe this reaction : A Endothermic, absorbing energy
Further explanationDelta H reaction (ΔH) is the amount of heat change between the system and its environment
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
∆H positive (endothermic): energy (heat) is absorbed from the environment to the system
∆H negative (exothermic): energy (heat) released from the system to the environment
Reaction
H₂O(g) + energy ⇒ H₂(g) + 1/2O₂(g)
In this reaction, it is shown that to break the bonds on the H₂O molecule to form H₂ and O₂ molecules will require energy (breaking the bonds requires energy)
This energy is usually called ∆H dissociation⁰
An organism is unicellular, reproduces asexually, and lives in a hot hydrothermal vent at the bottom of the ocean. This organism most likely belongs to the kingdom