Answer:
sorry don't know wish I could help
A carpenter uses sandpaper on a piece of wood. Before, the wood felt rough. After, the wood felt smooth. Did the friction between the hand and the wood increase or decrease after using the sandpaper? Describe what the sandpaper did to the wood to make it smoother.
Answer:
Friction between the hand and the wood decreased.
Explanation:
The texture of the wood went from rough → smooth! This means friction between the hand and the wood was notably decreased.
According to this prompt, the carpenter used sandpaper against the wood. Sandpaper just so happens to be a very abrasive substance. The sandpaper polished and leveled out the wood which wore all the jutting bits away.- overall, making it much smoother and more pleasant to touch!
Hope I was of assistance! Have a nice day and Spread the Love! <3
Answer question number 3
Answer:
A
Explanation:
A mixture is formed when two or more substances are physically mixed together. A compound is formed when two or more substances are chemically combined through a chemical reaction.
A car travels 45 miles per hour. What is this speed in feet per hour?
Answer:
64
hopeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
compound name of SO2
Why MgO will form after Mg reacting with CuO? (mcq)
Mg forms positive ions and O forms negative ions
Mg is more reactive than Cu
CuO have loose bonding
Answer:
Mg is more reactive than Cu
Explanation:
In the reaction between Mg and CuO to form MgO, MgO will form because Mg is more reactive than Cu.
This kind of reaction is called a single replacement or single displacement reaction.
The replacement of a metallic ion in solution by a metal atom higher in the activity series than the metal in solution falls into this category of reactions. The element Mg is higher than Cu in the activity series. The higher an element is in the activity series, the more reactive they are. Since Mg is more reactive, it will displace the Cu from CuO.N2+H2》NH3
is it balanced or unbalanced
8. Describe how crystals of copper sulphate are prepared.
Answer:
Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.
Hope it helps
Which of the following is NOT an example of a chemical change? *
O Corrosion
O Grinding
O Combustion
O Rust
Refer to your periodic table:
Which of the following has the smallest atomic radius?
Bromine
Astatine
Iodine
Fluorine
iondine
Explanation:
bromine has 185pm, astatine haa 200, iondine has 140 and lastly fluorine has 147. so iondine has the smallest atomic radius
What are the benefits and dangers of the Iron element in our daily life?
what makes a substance a molecule? it’s 7th grade science
Answer:
Molecular substances are made when two or more atoms join together by covalent bonds.
Explanation:
I hope this helps. I took the same class.
HELP!!!
write the scientific names of these ionic compounds
Answer:
• Copper chloride
• Copper (II) chloride
• Iron (II) sulfide
• Iron (III) sulfide
Which group of atomic models is listed in historical order from the earliest to the most recent?
The historical order of atomic models from the earliest to the most recent is as: Hard sphere model, electron shell model, and wave mechanical model. Therefore, option (A) is correct.
What is the atomic model?The atomic model can be described as the model used to describe the structure and composition of the atom. The atom as a primary component of matter has been under extensive study to understand the universe.
In the classical model of an atom, the atom is made of smaller particles with an electrical charge called electrons, protons, and neutrons. To understand the atomic models, it is important to understand how these particles make up the atom.
There are five principal atomic models that have been proposed over time, which are Dalton’s atomic model, Thomson’s atomic model, Rutherford’s atomic model, Bohr’s atomic model, and the quantum atomic model.
Learn more about the atomic model, here:
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Your question was incomple, most probably the complete question was,
Which group of atomic models is listed in historical order from the earliest to the most recent?
A) Hard sphere model, electron shell model, and wave mechanical model
B) Hard sphere model, wave mechanical model, and electron shell model
C) Electron shell model, Hard sphere model, and wave mechanical model
D) Electron shell model, wave mechanical model, and Hard sphere model
A physical change is easier / more difficult to reverse than a chemical change.
Answer:
the answer is that a physical change is easier to reverse then a chemical change.
Explanation: In order for a physical change to take place it's easier to just undo what happened then if it was a chemical change because in order for very few chemical changes to reverse to it's original substance you would need another chemical change.
The transition metals (with the exception of Zn, Cd and Hg) are very much hard and have low volatility. Why Zn ,Cd and Hg has low melting points. (a) These have all their electrons paired. (b) These have maximum number of unpaired electrons. (c) These have very strong metallic bonding. (d) These have more metal-metal bonding.
Answer:
Zn ,Cd and Hg has low melting points because - These have all their electrons paired.
Explanation:
These have all their electrons paired -: All the electrons in the d-subshell are combined with Zn , Cd and Hg. The metallic bonds present in them are, therefore, weak. This is why they have low points of melting and bolting. therefore , this statement is true. These have maximum number of unpaired electrons. Since , these transition metals have all electrons paired , so this statement is incorrect.These have very strong metallic bonding -: Zn, Cd and Hg d-orbital are completely filled. They have poor metallic bonding and less compact packing due to their fully filled d-orbitals, so all of them are volatile in nature. Therefore, this statement is also not valid .These have more metal-metal bonding. -: Since , their metallic bond is weak , so this statement is not true .Hence , the correct option is A (These have all their electrons paired).
What are natural resources
Answer:
resources that come from the ground or eath naturally which also means that those minerals like coal take hundreds of years to be created
True or false
Each family represents the number of energy levels present in an atom of the element.
Answer:
true because of the elements
An element, X, has 2 isotopes, X-32 with an abundance of 31.5% and X-35 with an abundance
of 68.5%. What is the average atomic mass of element X?
Answer:
amu = 34.055 or 34.1
Explanation:
to calculate the average mass, first convert the percentages into decimals. Then, calculate the mass numbers. To get this number, multiply the decimal by the mass number for each isotope and, then add them together.
( 0.315 x 32 ) + (0.685 x 35 ) = 34.055
What is the relationship between the latitude and hours of daylight
Answer:
The tilt of the Earth's axis also defines the length of daylight.Daylight hours are shortest in each hemisphere winter. Between summer and winter
solistice the number of daylight hours decreases and the rate of decrease is larger the higher the latitude.The fewer sunlight hours the colder nights.
Name this element.
i need the answer like now
WILL MARK BRAINLIEST!!!! HELPPPP
what is the difference between simple distillation and fractional distillation
Answer:
A single distillation cycle is enough to separate the mixture. ... Simple distillation is the method used to separate substances in mixtures with significantly different boiling points, while fractional distillation is used for mixtures containing chemicals with boiling points close to each other.
Explanation:
Please help ASAP 100 points points help I will mark you as brainlister
this is lithium ion with a +1 charge
A roller coaster with a mass of 20kg sits at the top of a 30 m high hill. What is the Potential energy of the roller coaster?
(Formula: PE=mgh)
(g= 9.8m/s)
Answer:
The answer is 5880 JExplanation:
The potential energy of a body can be found by using the formula
PE = mgh
where
m is the mass
h is the height
g is the acceleration due to gravity which is 9.8 m/s²
We have
PE = 20 × 30 × 9.8
We have the final answer as
5880 JHope this helps you
How many atoms are present in 7.50 mol of chlorine atoms? _
Answer:
4.52 x 10²⁴ atoms Cl
Explanation:
A mole is a name that means a certain number like a dozen means 12. 1 mole of chlorine atoms is 6.022 x 10²³ chlorine atoms. The unit conversion is 6.022 x 10²³/mol.
[tex]7.50molCl*\frac{6.022 x 10^{23} atomsCl}{1molCl} = 4.5165*10^{24} atomsCl[/tex]
Round to 4.52 x 10²⁴ atoms Cl for the correct number significant figures.
6. A sheet of metal is 2 cm wide, 10 cm tall, and 15 cm long. It was 4 grams. What is the
density?
Answer:
0.013g/cm^3
Explanation:
density= mass÷volume
Answer:
0.01(3) g/cm3 (cm3 means centimeter cubed, (3) means the 3 goes on forever)
Explanation:
The volume of the sheet is 300 cm3, and dividing 4 grams by 300 cm3 gets you 0.01(3) g/cm3. Hope it helps!
Write the word equations for the following balanced chemical equations.
a. Zn + 2HCl → ZnCl2 + H2
b. 2503 2502 + O2
Answer:
21
Explanation:9+10
what happens to the molecules as water freezes PLS HELP THIS IS DO TODAY
During freezing, water molecules lose energy and do not vibrate or move around as vigorously. This allows more stable hydrogen-bonds to form between water molecules, as there is less energy to break the bonds. ... Thus water expands as it freezes, and ice floats atop water.
When water molecule freezes, the water molecules have slowed down enough that their attractions fixed them into fixed positions.
What do you mean by freezing ?The term freezing is defined as a phase transition where a liquid converted into a solid when its temperature is lowered below its freezing point.
The freezing point is the temperature at which a liquid turns solid. In the freezer, for example, water-filled ice cube trays.
Water molecules freeze in a hexagonal pattern, with molecules further apart than when the water was liquid. It is worth noting that the molecules in ice would be vibrating.
Thus, When water freezes, the water molecules slow down to the point where their attractions arrange them into fixed positions.
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A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass
Answer:
Mass = 0.000176 gram
Steps:
m = V × ρ
= 20 milliliter × 8.8 gram/cubic meter
= 2.0E-5 cubic meter × 8.8 gram/cubic meter
= 0.000176 gram
Explanation:
Why is the nitrogen cycle considered a closed system?
Answer:
because nitrogen is fixed by bacteria and assimilated by plants
Explanation:
Answer:
It is a considered a closed system because nitrogen is fixed by bacteria and is taken in by plants.
Explanation:
What is the effect of tap water, sea water, and rainwater on the rusting rate of iron?
(Please i need an answer π-π)
Answer:
The more acidic the solution the faster it rusts. More Na = more rust
Explanation: