Answer: Democritus atomic theory is the ancient theory that describes the nature of matter in terms of atoms whereas Dalton atomic theory is a modern scientific theory that describes the nature of matter in terms of atoms. According to Dalton's theory, atoms are identically same, but Democritus had no idea about it. Atoms are never created nor destroyed, they just rearrange.
Explanation:
an element has atomic number of 17 state the elements group and period number
Answer:
The element is in group 7, the halogens. The element is in the third period or row of the table.
Explanation:
Chlorine is element number 17.
Which of the following statements is true about the molecule shown below?
Answer:
B. The bonds are polar and the molecule is nonpolar.
Explanation:
Each bond in the molecule is polar, as indicated by the partial charges on the atoms of the molecule. However, the four atoms are arranged symmetrically around the central atom. In this case, the effects of the partial charges on opposite sides cancel out. As a result, the molecule as a whole is nonpolar. If exposed to an electric field, the molecule will not orient itself in any particular direction.
1.
John ground some coffee beans into little pieces. He put them into a coffee filter and poured
800 cm3 of boiling water over them to make a jug of coffee.
coffee filter
Coffee
Beans
ON
jug of coffee
(a) Complete the sentences below. For each sentence, choose one of the following
words.
insoluble
soluble
solution
solvent
(0)
The liquid in the jug is brown because parts of the coffee beans
are
in water.
1 mark
Metallic bonding occurs between atoms of
1.)sulfur
2.)copper
3.)fluorine
4.)carbon
Answer:
copper
Explanation:
metallic bonds occur among the metal atoms where iconic bonds join metal and nonmetals metallic bonding joins a bolt of metal atoms a sheet of aluminum foil and a copper wire are both place where you can see metallic bonding in action the Sea of electrons that is free to flow about the crystal of positive metal ions
Metallic bonding occurs between metal atoms. Among the given copper is example of metal in which copper atoms are strongly held by metallic bonds.
What are metals?Metals are electropositive elements. Metals contains a pool of mobile electrons among the sea of positive ions. Metals exhibit some peculiar features such as conductivity, hardness, malleability, ductility, luster etc.
Metals atoms form well orders crystalline structure in which particles are held together by strong metallic bonds. In periodic table, the first two groups and all the d-block elements are metals.
Copper is a transition metal in d-block. Copper is a very important metal in our lives and in industries since it is used in constructions, electronics, house hold items etc., because of its hardness and conductivity. Hence, option 2 is correct.
Find more on copper;
https://brainly.com/question/2289251
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From this list below, select the items which are properties of ionic compounds. * 5 points low melting point conductors of electricity when in liquid or aqueous state high melting point mostly liquids and gases at room temperature soluble in water
Answer:
conductors of electricity when in liquid or aqueous state
high melting point
soluble in water
Explanation:
An ionic substance is any substance that is composed of two ions of opposite charge.
In the solid state, ionic substances do not conduct electricity because the ions are trapped inside the crystal. When in liquid state or in aqueous solution, these ions are now free and the solution becomes an electrolyte.
All ionic substances have a very high melting point and dissolve in water easily.
What does it mean to be limiting or excess? (Limiting Reactant)
Answer:
Find the limiting reagent by calculating and comparing the amount of product each reactant will produce. Balance the chemical equation for the chemical reaction. The reactant that produces a lesser amount of product is the limiting reagent. The reactant that produces a larger amount of product is the excess reagent.
Explanation:
1. 2.00 L of gas is at 740 mm Hg. What is its volume at standard
pressure?
0.16
Explanation:
when you divided 1.2.00 with 740 you get this number.
HELP ITS DUE IN AN HOUR!!
What is a lattice position?
Explain
Explanation:
Crystallography. an arrangement in space of isolated points (lattice points ) in a regular pattern, showing the positions of atoms, molecules, or ions in the structure of a crystal.
If an atom experiences sufficient thermal activation, it can move to a neighboring lattice position.4 If the vibration frequency of the atom is v and the atom has Z nearest neighbors, the total number of jump attempts is vZ. However, only a small fraction of the attempts will be successful, with a probability depending on the ratio between the necessary activation energy for a single jump QD and the thermal activation kBT. The effective jump frequency ΓD is then
(5.6)
With each successful jump, the atom travels one atomic distance λ and the total traveling distance in unit time is thus ΓDλ. Substituting the jump frequency ΓD into the expression for the root mean square displacement of a random walker [equation (5.5)] and using the spatial coordinate r leads to
19. A piece of unknown metal with a mass of 62.0g and an initial temperature of 95.3°C is dropped into
100.0g of water with an initial temperature of 27.0°C. The final temperature of the system is 34.0°C.
Answer:
a
Explanation:
What is metal ? Where does it coke from ?
Answer:
Most pure metals, like aluminium, silver and copper, come from the Earth's crust. They are found in ores – solid materials called minerals, usually occurring in rock, from which the pure metal has to be extracted. The properties of pure metals can be improved by mixing them with other metals to make alloys.a metal is an element that readily forms positive ions (cations) and has metallic bonds
coke is a strong stimulant made from coca leaves
PLEASE HELP ASAP!!!!!!????
Answer:
The third one!
N2 + 3 H2 – 2 NH3 How many moles of nitrogen (N2) are required to get 6
moles of ammonia (NH3)? *
Answer:
N2 + 3H2 → 2NH3. 14 moles a. If 6 mol of H2 are consumed, how many moles of NH3 are produced? ... a 3 mol H₂. 4. How many moles of nitrogen are needed to make 11 moles of NH3? Il mol NH₃ x Imol Na = 15.5
How many atoms in 12 moles of Mg?
Help for extra points & brainlest !
Answer: i think is true
Explanation:
True. Cells have jobs in your body as they have functions to do.
please help and show work
What is the volume of 5.7 moles of Hydrogen gas?
two types of subatomic particles in the nucleas of an atom
Explanation:
protons and neutrons.....
...
Answer:
The subatomic particles are Protons and Neutrons.
Calculate the volume of a 0.15 mol dm-3 Ba(OH)2 solution required to completely neutralize 45 cm3 of a 0.29 mol dm-3 HNO3 solution. Note: Ba(OH)2 + 2HNO3 --> Ba(NO3)2 + 2H2O
Answer:
[tex]V_{base}=43.5cm^3[/tex]
Explanation:
Hello there!
In this case, given the neutralization chemical reaction of barium sulfate and nitric acid, it is possible to evidence the 1:2 mole ratio between them; thus, at the equivalence point we have:
[tex]2n_{base}=n_{acid}[/tex]
Which in terms of molarities and volumes is:
[tex]2M_{base}V_{base}=M_{acid}V_{acid}[/tex]
In such a way, by solving for the volume of base, we proceed as follows:
[tex]V_{base}=\frac{M_{acid}V_{acid}}{2M_{base}} \\\\V_{base}=\frac{45cm^3*0.29mol*dm^{-3}}{2*0.15mol*dm^{-3}} \\\\V_{base}=43.5cm^3[/tex]
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do i have to know the chemical and physical properties of alloys? only chemistry students answer this.
Answer:
yes you do so you know how strong it is how maluble it's is so it can be customised to it's specific use
Answer:
alloy's properties are usually different from those of its component elements. Alloy constituents are usually measured by mass. Unlike pure metals, most alloys do not have a single melting point; rather, they have a melting range in which the substance is a mixture of solid and liquid.
physical properties of alloys:-Alloy steels have a wide range of special properties, such as hardness, toughness, corrosion resistance, magnetizability, and ductility. Nonferrous alloys, mainly copper–nickel, bronze, and aluminum alloys, are much used in coinage.
chemical properties of alloys:-Pure metals are useful but their applications are often limited to each individual metal's properties. Alloys allow metal mixtures that have increased resistance to oxidation, increased strength, conductivity, and melting point; Essentially any property can be manipulated by adjusting alloy concentrations.
dnt learn all thr properties.
these are the main properties..u can learn thse only. hope it will help u
Why is it important to know characteristics that matter undergoes in chemistry? How can we analyze the relationships between chemical and physical changes and properties?
Answer:
It's important for scientists to know the properties of matter because all things are made up of matter. Each type of matter has different physical characteristics and scientists need to know and understand these characteristics to make calculations. ... The main phases of matter are solid, liquid, and gas.
how is salt obtained or manufactrured
Answer:
There are three methods used to produce salt: solar, evaporation and rock mining.
Explanation:
Which series reveals the source of energy for coal?
coal chemicals sun
coal plants chemicals
coal animals sun
coal plants sun
Answer:
coal chemicals sun
Explanation:
Which sentence in paragraph 1 explains what Americans are doing to help the environment?
O a. Today, 60 percent of us believe that climate change is a serious threat.
O b.In 1980, coal, oil and gas made up 89 percent of the energy we used.
0
c. 90 percent of us have recycled in the last year.
O d. Sometimes you can even find low belief in climate change.
Someone help please! Extra points & brainlest!
Answer:
golgi apparatus
Explanation:
Answer:
vacuole
Explanation:
the answer is vacuole im pretty sure!
PLEASE HELP I WILL MARK YOU BRAINLIEST !!If you react 4.25 moles of FeCl2, how many moles of Cl2 did you also react?
ILL GIVE 12 POINTS TOO PLEASE IM BEGGING FOR HELPPPPP
Which of the nine substances are made of four elements?
Answer:
Oxygen mucury carbon dioxide and platinum
Explanation:
CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g) In the reaction above, 0.5487 grams of calcium carbide are completely consumed to produce acetylene gas, C2H2. What volume (in mL) will this gas occupy if it is collected at 43 degrees Celsius and 0.926 atm pressure
Answer:
239.7mL
Explanation:
Using the general gas equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas constant (0.0821 Latm/molK)
T = temperature (K)
The balanced chemical equation in this question is as follows:
CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g)
From the equation, 1 mole of CaC2 produces 1 mole of ethylene gas, C2H2.
Using mole = mass/molar mass
Molar mass of CaC2 = 40 + 12(2)
= 40 + 24
= 64g/mol
mole = 0.5487/64
mole = 0.00857mol of CaC2
Hence, 0.00857mol of CaC2 produced 0.00857mol of C2H2
Based on the information provided, n = 0.00857mol, T = 43°C = 43 + 273 = 316K, p = 0.926 atm
PV = nRT
V = nRT/P
V = 0.00857 × 0.0821 × 316/0.926
V = 0.222/0.926
V = 0.2397L
In mL, volume = 0.2397 × 1000
= 239.7mL
Helpp plzz..10pointss
PLEASE HELP ME ASAP!!!!!! YOU GET 10 POINTS!!!!!!
For reaction below, describe how its equilibrium could be shifted in the indicated direction.
1. H2(g)+C12(g)<---------->2HC1(g)+thermal energy: shift to the left
2.C(s) +O2(g)<---------->CO2+thermal energy: shift to the right
Answer:
Here is the ANSWER KEY, it may also has other of the questions you don't know :)
Explanation:
https://sciencewithhorne.weebly.com/uploads/5/7/3/5/57358947/unit_11_hw_key.pdf
Use the following information to answer the following question.
Cu + 2 AgNO3 --> Cu(NO3)2 + 2 Ag
12.7 g of copper metal reacts with silver nitrate to actually produce 38.1 g of silver in the lab.
Percent Yield = Actual Yield/Theoretical Yield x 100%
What is the percent yield of silver (Ag) in this reaction?
Answer:
For these problems, we need to compare the theoretical yield that we'd get from performing stoichiometry to the actual yield stated in the problem. % yield is the actual yield/theoretical yield x 100%
Cu + 2 AgNO₠→ Cu(NOâ‚)â‚‚ + 2 Ag ==> each mole of copper yields two moles of silver
12.7-g Cu x ( 1 mol Cu /63.5-g Cu) x ( 2 mol Ag / 1 mol Cu) x (108-g Ag / 1 mol Ag) = 43.2-g Ag. This is the theoretical yield. Now, since we got 38.1-g Ag our % yield is:
38.1-g/43.2-g x 100% = 88.2%
Explanation:
.
Characteristics of a Group of Elements
Do not conduct electricity
• Mostly gas, but brittle when solid
Has 7 valence electrons
.
Which of these elements is in this groun?
Answer:
Gas
Explanation:
I dunno but a lucky guess i guess
