Answer:
5
Explanation:
I don't remember very thing from this unit but I believe 5 makes it possible
Please can anyone help me? How are the first 20 elements of the periodic table constructed?
Answer:
Based on the periodic law
Explanation:
All the elements on the periodic table were constructed based on the periodic law.
Henry Moseley in the 1900s re-stated the periodic law by changing the basis of the law from atomic weight to atomic number. The present periodic law is therefore "the properties of elements are a periodic function of their atomic number".
The atomic number is the number of protons in an atom. Based on the graduation of atomic number on the periodic table, elements are classified into groups and periods.What is the number of protons for the following?
190
+2
Os
76
Answer:
190+2=192
Explanation:
192 add it 192 added
Answer: they are right
Explanation:
Loose sugar dissolves much faster than a sugar cube because loose sugar?
A. Has greater surface area
B. Has less kinetic energy
C. Has a higher temperature
D. Has greater surface tension
Loose sugar dissolves much faster than a sugar cube because loose sugar (a) has greater surface area.
When any solute dissolve in ground into small pieces it dissolve faster in solvent than large pieces because in small ones the large surface area is exposed into solvent.
With the greater surface area is exposer, the contact in between the solute particles and the solvent is more. this is the reason that loose sugar cube dissolve much faster than sugar cube as sugar cube has less surface area in contact with solvent.
Thus, Loose sugar dissolves much faster than a sugar cube because loose sugar (a) has greater surface area.
To learn more about solubility here
https://brainly.com/question/8685116
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Which is the Lewis structure for H3PO4?
Answer:
There are four σ bonds and no lone pairs around phosphorous atom in the lewis structure of H3PO4 molecule. Therefore total number of VSPER pairs are four. Therefore, shape of molecule around phosphorous atom is tetrahedral.
Explanation:
There are four σ bonds and no lone pairs around phosphorous atom in the lewis structure of H3PO4 molecule. Therefore total number of VSPER pairs are four. Therefore, shape of molecule around phosphorous atom is tetrahedral.
therefore total number of vsper pairs of four. Therefore, shape of molecule around phosphorous atom is tetrahedral.
How are elements and compounds a part of our daily lives?
Answer:
Aluminium (A1) -Used in the production of duralumin alloy for use in the construction of aeroplane bodies. 3. Silicon (Si) -To make microchips 4. Sulphur (S) -To make matches, fireworks and for the manufacture of sulphuric acid 5.
Explanation:
Hope this helped!
Answer:
yes
Explanation:
we use different elements and compounds in our life ex salt and iron but most of the substances found in our environment are mixture btw scientists need to classified substances to work with our substances and to study pure substances hope it helps u
Help me with homework.
The chemical equation is said to be balanced if the number of atoms in the reactants and products is the same
Further explanationEquation balanced ⇒ total number of atoms in reactants(on the left)= total number of atoms in products(on the right)
H₂+O₂---> H₂O
Reactants : H₂, O₂
Products : H₂O
not balanced
H₂O₂ ---> H₂O+O₂
Reactants : H₂O₂
Products : H₂O, O₂
not balanced
Na+O₂ ---> Na₂O
Reactants : Na, O₂
Products : Na₂O
not balanced
N₂+H₂ ---> NH₃
Reactants : N₂, H₂
Products : NH₃
not balanced
P₄+O₂---> P₄O₁₀
Reactants : P₄, O₂
Products : P₄O₁₀
not balanced
Fe+H₂O ----> Fe₃O₄ + H₂
Reactants : Fe, H₂O
Products : Fe₃O₄
not balanced
What is different about Chlorine (CD) from Sodium (Na)?
- Chlorine is a non-metal and Sodium is a metal
- Chlorine is a metal and Sodium is a non-metal
- Chlorine (CI) is on the 3rd Energy Level whereas Sodium (Na) is on the 2nd Energy Level,
Explanation:
- sodium is an alikal metal and chlorine is a halogen
-sodium forms metallic bond while chlorine cant
- chlorine is an oxidant while sodium is a reducing agent
arrange the following in order of increasing mass . a. 16 water molecules b. 2 atoms of lead 3. 5.1*10^-23
Two individual atoms of the same element are slightly different. One has one more proton than it has electrons. The other has one more electron than it has protons. These atoms are both
ions
isotopes
freons
xenons
phlogistons
Answer:
ions
Explanation:
Individual atoms of the same element but having slightly different number of protons and electrons are called ions.
Ion is a charged particle.
An atom is made up of three fundamental subatomic particles. Protons are the positively charged particles Electrons are the negatively charged particles Neutrons do not carry any charges.When the number of protons > electrons the body is positively charged.
When the number of electrons > protons the body is negatively charged.
Charged particles are called ions.
what is the molecular formula of carbohydrate
Answer:
Carbohydrates can be represented by the stoichiometric formula (CH2O)n, where n is the number of carbons in the molecule. Therefore, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules.
Explanation:
May I have brainliest please? :)
Answer:
(CH2O)n, where n is the number of carbons in the molecule.
Explanation:
Also remember the 1:2:1 ratio of carbon:hydrogen:oxygen
iron is a :
A. substance
B. heterogenous mixture
C. homogenous mixture
Answer:
a: iron is a substance
Explanation:
because its hard and brittle and classified as a metal
Plz answer quickly! :))
How are the shapes of covalent compounds made?
Hope this might help a little
HELP ME PLEASE ! I NEED HELP !
Which statement best completes the diagram?
Mexican culture
Most people live in
urban areas.
The most widely
spoken language is
Spanish
?
A. The most important literature is nonfiction
B. The most popular foods are vegetarian,
C. The most common religion is Catholicism.
D. Most people work as farmers.
Answer:
The answer is (c)
Explanation:
Answer:
C. The most common religion is Catholism.
Explanation:
I'm taking the quiz rn.
A geologist was looking at a new
mineral they found. The mineral
sample was gray, non-metallic, had
density of 3.8 g/mL, and a volume
of 48.3 mL
Of the observed properties listed
below, which is considered to be an
extensive property?
A Gray
B Metallic
C Density
D Volume
Answer:
D. Volume
Explanation:
Properties mentioned in the question;
colour = gray
Nonmetallic
Density = 3.8 g/mL
Volume = 48.3 mL
Of the mentioned, which is extensive ?
Extensive properties are those properties that are proportional to the amount of substance present.
The correct option is D. Volume. The other properties do not change with increasing or decreasing amount of the mineral
A clam farmer has been keeping records of the water temperature and the number of clams developing from fertilized eggs. The data is recorded above.
What is the dependent variable?
What is the independent variable?
What is the optimum temperature for clam development?
Answer:
The dependent variable is the number of clams developing from fertilized eggs.
The independent variable is the water temperature
The optimum temperature for clam development is 30 degrees centigrade.
Explanation:
The graph of the number of clams developing from fertilized eggs and water temperature is attached to this answer.
The independent variable is being manipulated in an experiment. As it changes, it produces a corresponding change in the dependent variable.
Here, the water temperature is the independent variable. As it changes, the number of clams developing from fertilized eggs (dependent variable) also changes alongside.
The optimum temperature is the temperature at which the greatest number of clams developing from fertilized eggs is produced. We can see from the graph that this temperature is 30 degrees centigrade.
I am in the second period and belong to the same family as silicon
Answer:
carbon
Explanation:
carbon has 6e- hence belong to group 4 and period 2
Answer:
Boron
Explanation:
Both silicon and boron are metalloids, and boron belongs on the second row (period)
Explain how the isotopes and ions of an atom differ.
Answer:
istopes is a situation in which each of two or more forms of same element that contain equal number of proton....while ions of an atoms are with extra electrons or missing electrons so they tends to differ
what is the relationship between kinetic energy and velocity ?
In the reaction given below, 23.5 grams of iron(III) oxide (Fe2O3) are reacted with excess carbon. What is the theoretical yield of iron metal?
2 Fe2O3 + 3 C --> 4 Fe + 3 CO2
If 14.5 grams of iron are recovered when the reaction is complete, what is the percent yield?
**Both answer should be written as XX.X
Answer:
Theoretical yield = 16.76 g
Percent yield = 87%
Explanation:
Given data:
Mass of iron oxide = 23.5 g
Theoretical yield of iron = ?
Actual yield of iron = 14.5 g
Percent yield of iron = ?
Solution:
Chemical equation:
2Fe₂O₃ + 3C → 4Fe + 3CO₂
Number of moles of iron oxide:
Number of moles = mass/molar mass
Number of moles = 23.5 g/ 159.69 g/mol
Number of moles = 0.15 mol
Now we will compare the mole of iron oxide with iron metal.
Fe₂O₃ : Fe
2 : 4
0.15 : 4/2×0.15 = 0.3
Mass of iron:
Mass = number of moles × molar mass
Mass = 0.3 mol × 55.85 g/mol
Mass = 16.76 g
Percent yield:
percent yield = (actual yield / theoretical yield)× 100
Percent yield = (14.5 g / 16.76 g) × 100
Percent yield = 0.87 × 100
Percent yield = 87%
Answer:
I tried the answer above and it’s correct
Explanation:
Dating of rock layers which layer is the youngest f,A,s,h,b,d,c,e
Answer:
E is the anwser
This is due tomorrow so please help! : name a product where viscosity is important its creation or use explain why it is important
What do minerals do when they are heated?
Select ALL of the following statements that are incorrect.
Solids, liquids, and gases are all able to act as solutes in a solution.
Solids, liquids, and gases are all able to act as solvents in a solution.
Solids are not able to act as a solvent if a gas is the solute.
Gases are not able to act as a solvent if a solid is the solute.
Answer:the 4th one is incorrect,and the 1st one is incorrect hope this helps.
Adsorption is defined as a process in which gas molecules tend to adsorb on the surface of a solid solvent.
Therefore, the statement solids are not able to act as a solvent if a gas is the solute, is false.
On the other hand, gases can also act as a solvent if a solid is the solute.
Explanation:
Adsorption is defined as a process in which gas molecules tend to adsorb on the surface of a solid solvent.
Therefore, the statement solids are not able to act as a solvent if a gas is the solute, is false.
On the other hand, gases can also act as a solvent if a solid is the solute.For example, air present in the surrounding acts as a solvent and solid substances present in the surrounding acts as a solute.
Hence, the statement gases are not able to act as a solvent if a solid is the solute, is false.
Thus, we can conclude that following are the statements which are incorrect.
Solids are not able to act as a solvent if a gas is the solute.
Gases are not able to act as a solvent if a solid is the solute.
write the complete balanced equation for the decomposition of AI(CIO3)3.
Answer:
2AL(ClO3)3 → 2ALCl3 + 9O2
Explanation:
How many grams of glucose are in 4.5x1023 molecules of glucose?:
Answer:
[tex].5865 \\ \\ \\ \\ \\ \5865[/tex]
[tex] \\ \\ 5865 \inf \inft \cos( \\ \) [/tex]
your older sister has just got her driver's licence. write a paragraph in your notebook to explain what she should do to make sure she travels safely. especially whe the roads are wet and the road surface is rough in some areas and smooth in others.
20cm3 of hydrochloric acid neutralized 25cm3 0.1moldm-3 sodium trioxocarbonate(IV) solution, find (i) the concentration of hydrochloric acid in moldm-3. (ii) the concentration of hydrochloric acid in gdm-3. (H=1.00, Cl=35.5)The equation for the reaction: 2HCl + Na2 CO3 → 2NaCl + H2O
Answer:
1. 0.25 moldm¯³.
2. 9.125 gdm¯³.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Na2CO3 → 2NaCl + H2O + CO2
From the balanced equation,
The mole ratio of the acid, HCl (nA) = 2
The mole ratio of the base, Na2CO3 (nB) = 1
1. Determination of the concentration of the acid, HCl in moldm¯³.
Volume of acid, HCl (Va) = 20 cm³
Volume of base, Na2CO3 (Va) = 25 cm³
Concentration of base, Na2CO3 (Cb) = 0.1 moldm¯³
The mole ratio of the acid, HCl (nA) = 2
The mole ratio of the base, Na2CO3 (nB) = 1
Concentration of acid, HCl (Ca) =?
Cava /CbVb = nA/nB
Ca × 20 / 0.1 × 25 = 2/1
Ca × 20 / 2.5 = 2
Cross multiply
Ca × 20 = 2.5 × 2
Ca × 20 = 5
Divide both side by 20
Ca = 5/20
Ca = 0.25 moldm¯³
Thus, the concentration of the acid, HCl in moldm¯³ is 0.25 moldm¯³
2. Determination of the concentration of the acid, HCl in gdm¯³
Concentration of the acid, HCl = 0.25 moldm¯³
Molar mass of HCl = 1 + 35.5 = 36.5 g/mol
Concentration of the acid, HCl in gdm¯³ =?
Conc. in moldm¯³ = Conc. in gdm¯³ /Molar mass
0.25 = Conc. in gdm¯³ /36.5
Cross multiply
Conc. in gdm¯³ = 0.25 × 36.5
Conc. in gdm¯³ = 9.125 gdm¯³.
The net force on a vehicle that is accelerating at a rate of 1.2 m/s² is 1500 newtons. What is the mass
of the vehicle to the nearest kilogram?
Answer:
1250kg
Explanation:
Given parameters:
Acceleration = 1.2m/s²
Force = 1500N
Unknown:
Mass on the vehicle = ?
Solution:
According to newton's second law of motion:
Force = mass x acceleration
Since mass is the unknown, insert the parameters and solve;
1500 = mass x 1.2
mass = [tex]\frac{1500}{1.2}[/tex] = 1250kg
Green light has a frequency of 6.01x10^14Hz what is the wavelength
Answer:
λ = 0.5×10⁻⁶ m
Explanation:
Given data:
Frequency of light = 6.01 ×10¹⁴ Hz
Wavelength of light = ?
Solution:
Formula:
Speed of light = wavelength × frequency
Speed of light = 3×10⁸ m/s
3×10⁸ m/s = λ × 6.01 ×10¹⁴ Hz
λ = 3×10⁸ m/s / 6.01 ×10¹⁴ Hz
Hz = 1/s
λ = 0.5×10⁻⁶ m
How many moles of Glucose (C6H120.) are in 13.0x1024 atoms of Glucose (C6H120)?
Express your answer in rounded to two decimal places
Answer:
21.59 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{13 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 21.594684...[/tex]
We have the final answer as
21.59 molesHope this helps you