A cube has a mass of 42 grams and a volume of 15 cubic centimeters. What is it’s density?
(Show your work or complete all problems for brainliest)
Answer:
2.8g/cm³
Explanation:
Given parameters:
Mass of cube = 42g
Volume of cube = 15cm³
Unknown:
Density of the cube = ?
Solution:
Density is defined as the mass per unit volume of a substance. It is mathematically expressed as:
Density = [tex]\frac{mass}{volume}[/tex]
So;
Density = [tex]\frac{42}{15}[/tex] = 2.8g/cm³
Sodium metal is added to a solution of magnesium chloride. Will a reaction occur? If so, what reaction will take place?
Please help me ASAP
What are redox half-reactions?
Answer:
C. Equations that separate the oxidation and reduction parts of the reaction.
Explanation:
Redox half-reactions are actually used when balancing redox reactions. It gives the oxidation or reduction reaction components/parts of a redox reaction. The change in oxidation and reduction states in the substances that are involved in a redox reaction is used to obtain a redox half-reaction.
This redox half-reaction can also be used to explain what takes place in an electrochemical cell; how the anode is undergoing oxidation and how the cathode is undergoing reduction.
Below is an example of a redox half-reaction:
2 Fe³⁺(aq) + 6e⁻ → 2 Fe(s) (Reduction)
3 Mg(s) → 3 Mg²⁺(aq) + 6e⁻ (Oxidation)
at stp what is the volume of 5.35 moles of methane ch4
Answer:
22.4 L
Explanation:
can we seperate naphthalene from sugar by filtration to obtain pure sugar?
Answer:
As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.
Laura has three beakers. Each contains 200 cm3 of a colourless liquid. Suggest how Laura could nd out which beakers contain pure water, and which contain solutions.
Answer:
See explanation
Explanation:
A pure liquid has a sharp boiling point. Now we know that the boiling point of water is 100°C.
If Laura begins to heat each liquid with a thermometer inserted into each liquid, the liquid that boils at exactly 100°C is pure water while the rest are solutions.
What is an animal-like, unicellular protist called?
protozoan
euglenoid
slime mold
decompos
Answer:
protozoan
Explanation:
An animal - like unicellular protist is called a protozoan. Such organisms shows similarities with animals.
Protozoans are unicellular organisms. They are similar to animals in that they perform nearly all life functions that makes animals very unique. They are mostly heterotrophs which feed on foods that have been produced by autotrophs. Examples are flagellates and ciliates.calculate the number of particles in each of the following a. 18 gram of O2 molecules b. 0.1 mole of Calcium atomic
Answer:
3.39 x 10²³ particles
6.02 x 10²²particles
Explanation:
The problem here entails we find the number of particles in the given substances.
From the mole concept;
1 mole of a substance contains 6.02 x 10²³ particles
a. 18g of O₂;
We first find the number of moles of this substance first;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of O₂ = 2(16) = 32g/mol
Number of moles = [tex]\frac{18}{32}[/tex] = 0.56mole
So;
1 mole of a substance contains 6.02 x 10²³ particles
0.56 mole of O₂ will contain 0.56 x 6.02 x 10²³ particles
= 3.39 x 10²³ particles
b. 0.1mole of calcium atom:
1 mole of a substance contains 6.02 x 10²³ particles
0.1 mole of the substance will contain 0.1 x 6.02 x 10²³ particles
= 6.02 x 10²²particles
when an electron gets closer to the nucleus does the attraction or repulsion grow weaker or stronger?
Answer:
Weaker
Explanation:
Since the charges on nucleus and electron are opposite in nature, an attractive force exists between them. It is true in generally, that when objects are made to move closer together in the direction of an attractive force, potential energy decreases (and increases whenever attracting objects are force to move apart).
Here, we are required to determine if the attraction or repulsion grow weaker or stronger.
When electrons get closer to the nucleus, the attraction grows stronger.First, we must establish scenarios when there can be attraction and ones where there can be repulsion.
By the law guiding electric charges; In electrical interactions:
Like poles repel while Unlike poles attract.
Also, in the atomic model; the nucleus is positively charged as it contains protons (+vely charged) and neutrons which are uncharged particles.Since the nucleus is positively charged and the electrons revolve round their orbit. Therefore, the force is an attraction force.As we all know that the force of attraction or of repulsion as the case may be is inversely proportional to the distance between the charged particles (the electrons and the nucleus in this case)When an electron gets closer to the nucleus, the distance between the electron and the nucleus reduces; and the force of attraction between the electron and the nucleus increases.Ultimately, when an electron gets closer to the nucleus, the attraction force will grow stronger due to the reduced distance between the electron and the nucleus.
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Answer:
sample 2
Explanation:
hope this helps
How many hydrogen atoms are there in 2 molecules of C3H6?
Answer:
there are 12 hydrogen atoms in 2 molecules of C3H6
Explanation:
"30 mph north" is an example of:
O velocity
speed
distance
O displacement
Answer:
distance velocity displacement, all three
Explanation:
help me fill this out please, i give brainliest
Answer:
Okay, Left top= waning gibbous
left second= new moon
left third= third quarter
left fourth= waxing crescent
right top= Waning crescent
right second= first quarter
right third= full moon
right fourth= Waxing gibbous
hope you do good :)
Answer:
first one waining gibbious
secound one waining crecent
third one new moon
fourth one first quarter
fithe one third quarter
sixth one full moon
sevnth one waxing crecent
eithe one waxing gibbious
Explanation:
You are running late to school and need to go 1,500 m in 10 minutes. What speed will you travel?
10 m/min
15 m/min
150 m/min
O 1 m/min
Answer:
15 m/min
Explanation:
You take the 1500 divide by 10 and your answer is 15
Which of these is a characteristic of science? (5 points) Question 1 options: 1) It cannot be reproduced by any scientist. 2) It cannot be changed by new knowledge. 3) It is based on empirical evidence. 4) It is guided by a set of values.
Answer:
3
Explanation:
It is based on empirical evidence
The characteristic of science is that it is based on empirical evidences comprising of a hypothesis.
What is a hypothesis?
Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
Learn more about hypothesis,here:
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how many moles of sodium are present in a sample of sodium having a mass of 137 g? (molar mass is 23.0g)
Answer:
5.95 moles
Explanation:
No of moles = given mass / molar mass
No of moles = 137/23
= 5.95 moles
Which of the following is a polar molecule?
A. A linear Carbon dioxide molecule (C02)
B. A carbon monoxide molecule (CO)
C. A calcium oxide molecule (CaO)
D. An oxygen molecule (02)
Answer:
B. A carbon monoxide molecule(CO)
Explanation:
CO is polar because oxygen is more electronegative than carbon, so it gives oxygen a partial negative charge and carbon and partial positive charge. This causes a net dipole moment. CO2 is linear with no net dipole moment because each C-O bond is equal and opposite to each other, so they equal 0, which makes them non polar.
Carbon dioxide is used by plants for ___?
Answer:
photosynthesis
Explanation:
that's the way plants feed themselves
Answer:
photosynthesis
Explanation:
I hope i helped
What is the molar mass of MgI2
Answer:
278.1g/mol
Explanation:
To find the molar mass of the given compound, we must know the atomic mass of the elements within the compound.
Atomic mass of Mg = 24.3g/mol
Atomic mass of I = 126.9g/mol
So;
Molar mass = 24.3 + 2(126.9) = 278.1g/mol
The molar mass of the compound is 278.1g/mol
A dolphin travels a distance 20 miles up the coastline in 153 minutes.If 1 mile is equal to 1609 meters,then what is the dolphins average speed in meters/seconds rounded to the nearest tenth?
Answer:
The dolphins average speed is 3.51 [tex]\frac{meters}{seconds}[/tex]
Explanation:
First of all, the following rules of three should be applied:
If 1 mile is equal to 1609 meters, 20 miles are equal to how many meters?[tex]distance=\frac{20 miles*1609 meters}{1 mile}[/tex]
distance=32,180 meters
If 1 minute is equal to 60 seconds, 153 minutes is equal to how many seconds?[tex]time=\frac{153 minutes*60 seconds}{1 minute}[/tex]
time= 9,180 seconds
Speed is a physical quantity that expresses the relationship between the space traveled by an object and the time used for it. That is, speed implies the change of position of an object in space within a certain amount of time and is calculated as:
[tex]speed=\frac{distance}{time}[/tex]
So in this case the velocity is calculated as:
[tex]speed=\frac{32,180 meters}{9,180 seconds}[/tex]
Solving, you get:
Speed= 3.51 [tex]\frac{meters}{seconds}[/tex]
The dolphins average speed is 3.51 [tex]\frac{meters}{seconds}[/tex]
Does sound travel faster in a warm room or a cold room?
Explain your answer.
2 paragraphs answer ASAPP
Answer:
Sound is vibrations that travel through a medium, and which are then converted into electrical signals by our brain so that we interpret them as a noise that we hear. These vibrations consist of particles colliding with each other (this is why sound cannot travel through space; there are no particles). At warmer temperatures, the particles that make up air will move faster, so these collisions will happen more frequently. Therefore the vibrations occur more quickly, so sound travels faster and reaches our ears in a shorter amount of time.
The speed of sound can travel faster in hot air than it can in cold air. This is because the molecules of air can move even faster and the vibrations of the sound wave can transmit faster. Sound is a type of mechanical wave, meaning that it requires a medium to transmit energy. Mediums are any substance that has mass and takes up space, from the air in the room to the metal atoms in an iron fence.
Explanation:
hope that helps :)
Answer:
Sound travels faster in a warm room because temperature affects the speed of a wave. In a warm room, the particles of air move faster and have higher chances of bumping into each other, which then increases the instances of energy transfer.
Explanation:
just trust me cuz
Does it take shorter or longer time to travel when the velocity is low?
Answer:
yes
explanation:
yes because when the velocity is low, all the energy is low and nothing can't do nothing without energy
A 1,600-milliliter bucket of paint is at a temperature of 70°F. Then the paint is divided equally into four smaller buckets. Each bucket is at 70°F before the paint is poured.
the temperature of each 400 milliliter bucket is about _____ the temperature of the original bucket of paint.
a.the same as
b.four times
c.one fourth
science
Answer:
a.the same as
Explanation:
The temperature of each 400mL bucket is about the same as the temperature of the original bucket of paint.
This is because the temperature of the paint inside the bucket is not dependent on the amount of paint present.
In this regard, the temperature is an intensive property. So each of the boxes will have a temperature that is the same as that of the original bucket. Each of the particles have the same amount of kinetic energy.What is the percent composition of nitrogen in N 2 O
Answer:
63.6%
Explanation:
The given compound is:
N₂O;
The problem here is to find the percent composition of nitrogen in the compound.
First find the molar mass of the compound:
Molar mass of N₂O = 2(14) + 16 = 44g/mol
So;
Percentage composition of Nitrogen = [tex]\frac{2 x 14}{44}[/tex] x 100 = 63.6%
How does the number of tin atoms in the sample compare to the number of aluminum atoms in a 20 gram sample of each (Sn:Al)
The number of Al atoms is greater than the number of Sn atoms
Further explanationGiven
20 gram sample of Tin and Aluminum
Required
Number of atoms
Solution
1 mol = 6.02 x 10²³ particles (atoms, molecules, ions)
So the number of atoms of each element is determined by the number of moles. The greater the number of moles the greater the number of atoms
moles Sn-Tin(Ar = 118,71 u)mol = mass : Ar
mol = 20 : 118,71 u
mol = 0.168
moles of Al-Aluminum(Ar=26.9815 u)mol = 20 : 26.9815 u
mol = 0.741
So the number of Al atoms > number of Sn atoms
pleae help me I'm so confused
What is the velocity of a person that runs 40 km in 100 hours?
Answer:
0.4 km/h velocity is also the direction their going, in this case the person, that I'll name billy bob joe, is going in so yeh
Explanation:
give me brainliest?
why water is not used as a thermometric substance
Answer:
Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.
Explanation:
Hope this help
Differentiate between worldwide conservation and national conservation policy.
Bohr's model of the atom attempts to explain the idea that:
A) protons and neutrons are found in the nucleus
B) all atoms of one type of element are identical
C) energy is quantized
D) the atom is mostly empty space
It attempts to explain the idea that:C. energy is quantized
Which combination of elements produce compounds with a large electronegativity difference and high conductivity?
Answer:
C. H2(g)
Explanation: