Answer:
A physical change is when the form of an object changes, but the substance stays the same.
Example: Ice melting into water.
Obi is trying to determine if a powdery, solid substance is an element or a compound. After recording some observations, he strongly heats a sample of the solid over a burner flame. After fifteen minutes, he turns off the flame and allows the sample to cool. He records his final observations in the data table.
Which is the best explanation of his results?
The heating changed some of the sample to gas, causing the mass to decrease without breaking down the sample. Therefore, the original sample is a compound.
The appearance stayed the same, showing that the sample was not broken down by heating. Therefore, the original substance is an element.
The mass decreased during heating and some of the impurities escaped. Therefore, the original substance is an element.
The chemical reaction with acid changed, showing that the sample was broken down by heating. Therefore, the original substance is a compound
Answer: I am thinking C maybe.
Explanation: I don't if this is right but I think it is C.
Answer:
D
Explanation:
Took the test on edge...
Question 1 (4 points)
Which of the following is/are true about Van der Waals forces?
A. They are very weak
B. They are a a type of momentary dipole
C. Both 1 and 2 are correct
D. neither 1 nor 2 is correct
Answer:
C. Both 1 and 2 are correct.
¿Qué podría pasar si la fuerza fuerte no existiera?
Answer:
andariamos flotando
Explanation:
For the n = 3 electron shell, which of the following quantum numbers are valid? Check all that apply.
Answer:
The valid quantum numbers are l=0, l=-2 and l= 2.
Explanation:
Given that,
n = 3 electron shell
Suppose, the valid quantum numbers are
l = 3
m = 3
l = 0
m = –2
l = –1
m = 2
We know that,
The value of n = 3
Principle quantum number :
Then the principal quantum number is 3. Which is shows the M shell.
So, n = 3
Azimuthal quantum number :
The azimuthal quantum number is l.
[tex]l=0,1,2[/tex]
Magnetic quantum number :
The magnetic quantum number is
[tex]m=-2,-1,0,1,2[/tex]
Hence, The valid quantum numbers are l=0, l=-2 and l= 2.
Answer: I = 0 m = -2 m = 2
Explanation: Edge.
the correct answers to the second part of this are:
n = 1, I = 0, m = 0
n = 3, I = 0, m = 0
n = 5, I = 4, m = -3
Can somebody please help me with this ASAP!
The electronic structure of the atom X is : 2, 8, 1
A. In which group atom x is found:—————-
B. In which period atom x is found:—————
C. What is the name of atom x:———————-
Answer:
A. grou(I)
B. 3rd period
C. Sodium (Na)
Explanation:
it belongs to group (I) since it has one valence electron
it belongs to 3rd period since it has three energy levels
Explain what happens if you change the number of protons in an element?
Plzzz helpppp!!!
Answer:
When you change the number of protons in an atom, you will change the atom from one element to a different element. Sometimes, when you add a proton to an element, the element will become radioactive. If you change the number of electrons in an atom, you will get an ion of the element.
What unit do we measure force in?
Answer: Newton
Explanation:
The SI unit of force is the newton, symbol N. The base units relevant to force are: The metre, unit of length — symbol m. The kilogram, unit of mass — symbol kg.
The number of protons in an element can be found by looking at the
symbol
atomic number
O average atomic mass
O name
Answer:
atomic number if it's a answer
Answer:
I think its the average atomic mass.
Explanation:
If I walk 10 meters down the hallway, then 2 meters into a classroom, what is my total distance walked in meters(write the number)
Answer:
12 meters
Explanation:
which two formulas represent compounds?
A.NaCI
B.HCI
C.H2
D.Ag
Answer: A and B
Explanation: A and b are Sodium chloride and Hydrogen chloride which are both compounds.
Answer: A. NaCI
Explanation: APEX
what is extremely lightweight and exists in a cloud orbiting the nucleus
Answer:
atomic particles
Explanation:
electrons are extremely lightweight and exist in a cloud orbiting the nucleus period the electron cloud has a radius 10,000 times greater than the nucleus according to the Los Alamos national laboratory.
A man weight 235.0 Ib Express his weight in kg.
How do you find it?
Answer:
The answer is 106.59 and 1 lb = 0.45359237 kg.
Explanation:
When you mix copper and tin, you make bronze. No chemical reaction occurs.
What is bronze?
O A. An element
B. A compound
O C. An alloy
O D. A molecule
SUBMIT
Answer:
C. Alloy
Explanation:
Bronze is an alloy because the creations of alloys are not chemical reactions. An alloy is made when a metal is combined with another metal or a nonmetal.
The mass of an atom Is found by adding Its protons and .The electric charge of an atom Is found by adding the charges carried by Its protons and .
Answer: the 1st answer is neutrons and i think the 2nd is nucleus
Explanation:
The mass of an atom is found by adding its protons and neutrons. The electric charge of an atom is found by adding the charges of its protons and electrons.
What is atomic mass?The atomic mass of an element is the total number of protons and the number of neutrons carried by one atom of that element. The atomic mass of an element is usually expressed in grams or a.m.u.
The atomic mass of an element = No. of protons + No. of neutrons
or
The atomic mass of an element = No. of electrons + No. of neutrons
The atomic number gives us information about how many protons are inside the nucleus of the atom. Elements are recognized by the number of protons in the nucleus. Neutrons are uncharged elementary or subatomic particles that are stable when bound in an atomic nucleus.
As the electrons and protons are charged particles in an atom, therefore, the sum of the charge carried by them is equal to the electrical charge of the atom.
For a neutral atom, the number of protons present in an atom is always equal to the number of electrons.
Learn more about atomic mass, here:
brainly.com/question/17067547
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Complete the sentence.
Atoms form chemical bonds to satisfy the
rule and to become
Answer:
Whats the sentence
Explanation:
Answer:
Atoms form chemical bonds to satisfy the octet rule and to become stable.
Got it right on Edg. 2020, hope this helps!
which of the following affects self esteem? O home, school, community and cultural environments O social interactions with family friends and others O media, tv, social networking sites all the above
Answer:
All the above
Explanation:
6. What is NOT an example of a solution?
a. Acetic acid and water
b, soil and water
b. Sugar and water
c. iron and carbon
ANSWER FAST PLEASE!!
Which is a true statement about a zero net force?
A zero net force causes a change to an object’s direction.
B.zero net force causes a change to an object’s speed.
C.A zero net force causes a change to an object’s acceleration.
D.A zero net force causes no change in an objects motion.
Answer:
D)a zero net force causes no change in an objects motion.
A zero net force causes no change in an object's motion. This statement is true about zero net force. Therefore, option D is correct.
What is zero net force ?An item that is originally at rest and has no net forces operating on it will stay at rest. If it is going, it will keep moving straight forward at a consistent speed. Forces are "pushes" or "pulls" on the object, and they are vector numbers, just like acceleration and velocity.
A automobile travelling at 50 mph on a highway continually has a net force of zero even though it is moving, since there is no acceleration and the speed is constant.
The total net force acting on an object as it moves at a steady speed is always zero. If you apply force, friction or another force (or several forces) will balance it out.
Thus, option D is correct.
To learn more about zero net force, follow the link;
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What is the most important scientific process
Answer:
atoms bonding
Explanation:
if the gas has a volume of 20 L at a temperature of 25 Celsius what is the volume of the gas when it is heated to 100°C if the pressure remains constant
Answer:
i have no idea
Explanation:
lol
Answer:
this has to do with gas law
Explanation:
Charles law
v1=20
T1=25
V2=?
T2=100
hence V1/T1=V2/T2
V2=V1*T2/T1
V2=20*25/100
V2=5
How many bromine atoms are present in 38.7 g of CH2Br2
Number of Br atoms : 2.679 x 10²³
Further explanationThe mole is the number of particles contained in a substance
1 mol = 6.02.10²³
Moles can also be determined from the amount of substance mass and its molar mass
[tex]\tt mol=\dfrac{mass}{MW}[/tex]
Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
mass of Br in CH₂Br₂[tex]\tt mass~Br=\dfrac{2.Ar~Br}{MW~CH_2Br_2}\times mass~CH_2Br_2\\\\mass~Br=\dfrac{2.80}{174}\times 38.7=35.59~g[/tex]
mol of Br[tex]\tt \dfrac{35.59}{80}=0.445[/tex]
number of atoms[tex]\tt 0.445\times 6.02\times 10^{23}=\boxed{\bold{2.679\times 10^{23}}}[/tex]
can anybody help me? ill mark brainliest!!! please ITS TIMED
Density = Mass/Volume but it can also be rearranged to:
Mass = Volume x Density
Given in the question:
Volume - 44.9 cc
Density - 19.3 g/cc
Calculation
Mass = Volume x Density
= 44.9 x 19.3
= 866.57 g
A piece of aluminum has a mass of 12.0 g. When it is placed into a graduated
cylinder with 14.0 mL of water, the water level rises to 18.5 mL. What is the density
of aluminum?
0 2.66667g/ml
O 2.67 g/mL
O 2.667g/mL
O 2.7 g/mL
Answer:
The answer is 2.7 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 12 g
volume = final volume of water - initial volume of water
volume = 18.5 - 14 = 4.5 mL
So we have
[tex]density = \frac{12}{4.5} \\ = 2.66666666...[/tex]
We have the final answer as
2.70 g/mLHope this helps you
How long does one complete orbit of Earth around
the sun take, give the amount in years and days?
Answer:365 days, 5 hours, 59 minutes and 16 seconds.
as distance from nucleus increases , energy of shells decreases, correct the wrong statement
as distance from nucleus increases , energy of shells also increases
Compare and Contrast Heating and
Cooling curves.
Answer: Heating curves show how the temperature changes as a substance is heated up. Cooling curves are the opposite. They show how the temperature changes as a substance is cooled down. Just like heating curves, cooling curves have horizontal flat parts where the state changes from gas to liquid, or from liquid to solid.
Explanation: Have a blessed day hopefully this helped!
How does the snake's skull allow it to eat large prey?
A. The jaw can crush the prey,
B. The teeth can grind the prey.
O C. The jaw can open wide around the prey.
D. The teeth can lock together around the prey,
You will analyze four substances in this lab. Based on their chemical formulas and what you already know about covalent and ionic compounds, make a prediction for each compound.Cornstarch, a carbohydrate consisting of hydrogen, carbon, and oxygen
Answer:
Oil: covalent
Cornstarch: Covalent
Sodium chloride: Ionic
Sodium bicarbonate: Ionic
Explanation:
Covalent compounds are formed by sharing of electrons between non metals whereas ionic compounds are formed by transfer of electrons from metals to non metals.
1. Oil, which is built from the nonmetals hydrogen, carbon, and oxygen: forms a covalent compound by sharing of electrons between non metals hydrogen, carbon, and oxygen. Covalent compounds are insoluble in water.
2. Cornstarch, a carbohydrate consisting of hydrogen, carbon, and oxygen: forms a covalent compound by sharing of electrons between non metals hydrogen, carbon, and oxygen. Covalent compounds are insoluble in water.
3. Sodium chloride (table salt), whose formula is NaCl is formed by transfer of electrons from sodium to chlorine.Ionic compounds are soluble in water.
4. Sodium bicarbonate, whose formula is is formed by transfer of electrons from sodium to .Ionic compounds are soluble in water.
Answer:
Oil, which is built from the nonmetals hydrogen, carbon, and oxygen:
covalent
Cornstarch, a carbohydrate consisting of hydrogen, carbon, and oxygen:
covalent
Sodium chloride (table salt), whose formula is NaCl:
ionic
Sodium bicarbonate (sodium bicarbonate), whose formula is NaHCO3:
ionic
Explanation:
What is the main point of mutation ?
quick please !!
Answer: type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA. The term point mutation also includes insertions or deletions of a single base pair.
Explanation:
Answer:
Mutation is important as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele.
Explanation:
Mutations put new DNA combinations into a population