Answer:
building really complicated legos
Explanation:
Ernest Rutherford built on the work of previous scientists and improved the accuracy of the atomic model. What part of the atom is Rutherford
credited for discovering?
A.) The protons
B.) The electrons
C.) The nucleus
D.)The electron cloud
what percent of a sample of a radioactive element whose half life=5.0 years will decay after 25 years?
Answer:
Calculate the rate of decay constant for U-238 if its half-life is 4.468 × 109 years. Answer: If the problem is referring to the half-life, then the ratio of = 0.5 because half of the original sample has already undergone decay.
Explanation:
Which molecule has the strongest forces of attraction between molecules?
Dipole-dipole interactions are the strongest intermolecular pressure of attraction.
Answer: Dipole-dipole interactions are the strongest intermolecular force of attraction.
Explanation:
When determining an element’s chemical properties, the most important subatomic particle to look at is
Answer:
Electrons
Explanation:
When determining the chemical properties of elements, the most important subatomic particle to consider is the electrons.
Electrons are negatively charged particles that orbits an atom. They occupy the extranuclear space of an atom.
These electrons determines the chemical properties of each atom. Most especially, the valence ones. All elements wants to resemble the noble gases, so they alter their number of electrons in order to attain this stable state.
Match the term with the definition.
Condensation
Evaporation
Sublimation
Freezing
A) A phase change from a gas to a liquid
B) A phase change from a solid to a gas
C) A phase change from a liquid to a gas
D) A phase change from a liquid to a solid
[Please Hellp!]
Carl makes the table below to determine the number of atoms of each element in the chemical formula 4Ca(ClO3)2.
A table with 3 columns and 2 rows. The first column labeled element has entries calcium, chlorine, oxygen. The second column labeled calculation has entries 1 times 4 , 1 times 2, 3 times 2. The third column labeled total atoms has entries 4, 2, 6.
What mistake did Carl make?
Answer:
calcium chloride oxide
Answer:
He did not multiply the chlorine and oxygen atoms by the coefficient 4
Explanation:
I just took the quiz
which element has a higher atomic number of aluminum or oxygen
Answer:
aluminum
Explanation:
oxygen's atomic number is 8.
aluminum's atomic number is 13.
A 75.0 gram sample of water at 25.0 degrees Celsius is mixed with a 100. Gram sample of water at 60.0 degrees Celsius. What is the final temperature of the water?
Answer:
The final temperature of the water = 45°C
Explanation:
Heat lost = heat gained
Heat lost by water at 60°C = m₁CΔT₁
Heat gained by water at 25°C = m₂CΔT₂
where m₁ is mass of water at 60°C = 100.0 g; m₂ is mass of water at 25°C = 75.0 g
C, specific heat capacity of water = 4.18 J/g°C
ΔT₁ = (60 - T); ΔT₂ = (T - 25); T = final temperature of the water
m₁CΔT₁ = m₂CΔT₂
100 * C * (60 - T) = 75 * C * (T - 25)
-100T + 6000 = 75T - 1875
-(100T + 75T) = -(6000 + 1875)
175T = 7875
T = 45°C
Therefore, final temperature of the water = 45°C
PLEASE HELP!!!!! NEED HELP ASAP!!!!!
Write the chemical formula for the ionic compounds below
EXAMPLE- Calcium Phosphide= Ca3P2
Magnesium chloride=
Aluminum Fluoride=
Lithium Bromide=
Potassium Sulfide=
Answer:
down below
Explanation:
MgCl2
AlF3
LiBr
K2S
Suggest whether water freezing is an endothermic or exothermic process. Can you explain your suggestion?
How many moles of
C
O
2
COX
2
will be produced from
97.0
g
97.0 g97, point, 0, start text, space, g, end text of
C
3
H
8
CX
3
HX
8
, assuming
O
2
OX
2
is available in excess?
Answer:
Im highy
Explanation:
Predict the products for the following chemical reaction: H2 + O2 →
a. H30
b. H20
c. H2OH
d. OH + OH
O a
Sea-Floor Spreading1. The arrows on the figure show the ocean floor spreading from the ridge. What are three kinds of evidence scientists have found to support this idea?
A. B. C.
I NEED HELP
Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Answer: 142.8%
Explanation:
13.8g H2 * (1 mol H2 / 2 g H2) * (2 mol H2O/ 2 mol H2) * (18 g H2O/1 mol H2O) = 124.2 g H2O
we just calculated our theoretical amount that should be formed and we are given the actual
percent yield: actual/theo * 100% = 124.2/87 * 100% = 142.8%
Which of the following laboratory procedures best illustrates the law of conservation of mass? (Assume the product of the reaction includes the mass of any unused reactants.) (3 points)
Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Weighing 100 g of Cu powder and 100 g of Fe filings
Heating 100 g of CaCO3 to produce 56 g of CaO
Dissolving 10 g of NaCl in 100 g of water
Answer: Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Explanation: I took the test just now, and the law of conservation of mass means to energy and that is exactly what they do in this answer!
Answer:
A
Explanation:
Which of the following are soluble in water: salt, gravel, or pepper
From smallest to largest put these in order of their atomic radius Mg, Ba,
Sr, Ca
O Ca, Mg, Ba, S
O Ra, Sr, Ca, Mg
Mg, Ca, Sr, Ra
Mg, Sr, Ra, Ca
Answer:
b
Explanation:
i jus did it
What is one danger associated with the use of hydrogen gas
Answer:
Topping the list of concerns is hydrogen burns. In the presence of an oxidizer -- oxygen is a good one -- hydrogen can catch fire, sometimes explosively, and it burns more easily than gasoline does.
Answer:
hydrogen burns
hope it helps
A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a ____________ of the substance.
Answer:
A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a mole of the substance.
Explanation:
The mole (symbol: mol) is the unit of measurement for amount of substance in the International System of Units (SI). A mole of a substance or a mole of particles is defined as exactly 6.02214076×1023 particles, which may be atoms, molecules, ions, or electrons. In short, for particles, 1 mol = 6.02214076×1023.
HELPP!!! ASAP!!!! BRAINLIEST!!!
Complete the following sentences. Energy is required to _______ bonds in a molecule and released when bonds are _______.
Answer:
Energy is required to break bonds in a molecule and released when bonds are made.
Explanation:
Energy is added to break bonds and released when making bonds.
Which atom in the following sets has the larger atomic radius?
a. Rn, Ne, Ar, Kr
b. Hg, Cs, Po, W
c. Mg, P, Al, Ar
Answer:
A.Rn,Ne,Ar,Kr.......
how can air produce a pressure
IN OWN WORDS NOT FROM GOOGLE
Answer:
Gas pressure is caused when gas particles hit the wall of their contains. the more often the particles hit the walls, and the faster they are moving when they do this , the higher the pressure .
Explanation:
The breaking and forming of bonds between atoms in substances results in changes in the _______ contained in the substances.
Answer:
Electrons
Explanation:
The breaking and forming of bonds between atoms in substances results in changes in the number of electrons in the substance.
Atoms combined in order to share, gain or lose electrons for it to be stable. The noble gases have a set up configuration which makes them stable. All atom tend to mimic the noble gases.Classify each organic compound based on the functional group it contains.
ether
carboxylic acid
ester
alcohol
Molecular Structure
Type of Compound
I-O-I
Η Ο
1 10
C-C-0-H
1
H
H
-I
H
II
H
1
H-C
1
H
H
1
-C
1
H
1
H
1
H
1
H
H
I
H-C
1
H
H H
I
C-0-C-H
1
1
H H
1
H-CC-O-H
1
H H
Answer:
H2C2O1
Explanation:
Answer:
Carboxylic Acid
Ester
Ether
Alcohol
Explanation:
Which compound is
ionic?
Answer:
chemistry
Explanation:
If 30cm³ of 0.45 mol dm3 HCl reacted with NaOH, how many moles of HCl reacted?
Moles HCl reacted : 0.0135
Further explanationMolarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large {\boxed {\bold {M ~ = ~ \dfrac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
So to find the number of moles can be expressed as
n = V x M
The volume of HCl 30 cm³=3.10⁻² dm³
Molarity of HCl = 0.45 mol/dm³
so moles HCl reacted :
[tex]\tt n=3.10^{-2}\times 0.45=0.0135[/tex]
what are chiral carbon
Answer:
A chiral carbon is a carbon bonded to four different groups ( four groups as carbon forms four bonds). The molecules formed are non superimposible on its mirror image.
8)How many grams are in 0.02 moles of beryllium iodide, BeI2?
9)How many moles are in 68 grams of copper (II) hydroxide, Cu(OH)2?
10)How many grams are in 3.3 moles of potassium sulfide, K2S?
11) How many grams are in 2.3 x 10-4 moles of calcium phosphate, Ca3(PO3)2?
Answer:
0.03:---$7--$-$7$--$-$-$$-$+-$$7-$$-$7-$8$+$-$
please someone help me its due today thanks :D
Answer:
D
Explanation:
All of the above are great examples!
"Endothermic reactions are those which absorb heat during the reaction."
Is copper sulphate malleable?
Answer:
Yes, Copper (Cu) in its pure form is a reddish-brown metallic element with high ductility and malleability that is an excellent conductor of heat and electricity: atomic weight 63.54; atomic number 29; density 8.94 g/cm3; melting point 1083°C; and boiling point 2595°C.
Answer:
no ,its not malleable
Explanation:
copper II sulphate is a blue compound , which is brittle solid , crystalline .
copper metal is malleable and ductile