Physical and chemical changes and properties are observed and tested in order to confirm the identity of a substance or how a substance may act in certain condition. The image below is a rock that, based on its bright yellow color, scientists believe to be sulfur. However, they would like to use a test to confirm this prediction.
Which procedure would you recommend the scientists use?
(A) Use volume displacement and the mass of the rock to calculate density.
(B) Measure volume in centimeters cubed and add to mass to determine density.
(C) Find the weight and volume of the rock then multiply to calculate density.
(D) Dissolve the rock in water, then find the mass and volume needed to calculate density.
Answer:
(A) Use volume displacement and the mass of the rock to calculate density.
Explanation:
Which is the vector quantity that describes the shortest path between two points?
The shortest distance taken by the object to reach the destination at a minimum time is called acceleration. Thus value acceleration depends upon the displacement and time.
write the metals and nonmetals and metalloids in the first 30 elements
Answer: Metals: Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Zn
Non-metals: H, He, C, N, O, F, Ne, Si, P, S, Cl, Ar
Metalloid: B
Explanation: The first 30 elements are H, He, Li, Be, B, C, N, O, F, Ne, Na,
Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Zn
Metallic elements are more electropositive (tending to form ions by donating electrons) with fewer electrons in their outer shell
Non-metallic elements are more electronegative (tending to form ions by accepting electrons) with more electrons in their outer shell
Metalloids are elements somewhere between, but without any specific clear boundary between them and metals/non-metals
group1 and group2 elements, with one or two outer electrons, are all metals: Li, Na, K, Be, Mg, Ca
similarly the transition metals 21-30 are all electropositive and metals.
The noble gases He, Ne, Ar are gases that have completed outer shells and are non-metallic, likewise the halogens F, Cl with 7 outer electrons, and O and S with 6 are non-metals. N and P (5 outer electrons) are non-metallic as are C and Si (4 outer electrons).
This leaves H, B, Al. H, with its single electron close to the nucleus is a non- metallic gas. Al (3 outer electrons) is metallic, but B, has its 3 electrons close to the nucleus and has the in-between character of a metalloid.
17.
Which of the following gases is used
in the demonstration of fountain
experiment?
A. CH
B. CO
C. HUS
D. NH3
E. SO2
Answer:
ammonia gas and hydrogen chloride gas.
A 20 N object is placed on a surface and starts to slide. What is the MOST likely reason the object begins to move?
A O Gravity exerts a balanced force on the object.
В.
Friction is applied to the object.
c. An unbalanced force causes acceleration.
D
The forces acting on the object are in equilibrium.
Answer:
c.
Explanation:
If the object starts to slide it must be on a slope.
There are 2 forces acting on the object - gravity and the friction between the object and the surface.
If sliding starts then the forces must be unbalanced.
The force of gravity is greater than the friction.
Answer:c
Explanation:
2CuO+2NH3------ 3Cu + 3H2O+ N2. Given that the relative molecular mass of copper oxide is 80, what volume of ammonia is required to completely reduce 120 g of Copper oxide? ( Cu=64, O=16, N=14)
Volume of Ammonia(NH₃) = 22.4 L
Further explanationGiven
Reaction
3CuO+2NH₃⇒ 3Cu + 3H₂O+ N₂
In the problem, the CuO coefficient should be 3 not 2
M CuO = 80
mass CuO = 120 g
Required
The volume of NH₃
Solution
mol CuO :
[tex]\tt mol=\dfrac{mass}{M}\\\\mol=\frac{120}{80}\\\\mol=1.5[/tex]
From the equation, mol ratio CuO : NH₃ = 3 : 2, so mol NH₃=
[tex]\tt \dfrac{2}{3}\times 1.5=1~mol[/tex]
Assume at STP(0 °C, 1 atm) ⇒1 mol = 22.4 L, then volume of NH₃=22.4 L
Drag and drop the correct component and reactants to fill in the equation for photosynthesis
Answer:
6CO2 + 6H2O ----> C6H12O6 + 6O2
Explanation:
Photosynthesis is the process by which green plants manufacture their own food using sunlight in the presence of carbon dioxide water and chlorophyll.
Chlorophyll is the pigment in plants that absorbs light.
The equation of photosynthesis is shown in the answer section above. Sugar and oxygen are the first products of photosynthesis.
why is a frozen popsicle a homogeneous mixture and not a pure substance
Answer:
You can not see the sugar.
Explanation:
when it is cold in your house
Answer:
yep.
Explanation:
I love to wear oversized hoodies and I get soft comfy blankets and watch movies. Have a nice night! :)
Para preparar 1 kilogramo de arcilla se requieren 400 gramos de agua. Si a nivel del laboratorio solo se cuenta con una probeta y sabemos que la densidad del agua es 1100Kg/m3 ¿Cuántos litros de agua se deben añadir?
Answer:
0.364 L
Explanation:
Para resolver este problema es necesario expresar la densidad en g/L.
Para hacer esa conversión primero convertimos m³ en L:
1 m³ = 1000 L1100 [tex]\frac{kg}{m^3}* \frac{1m^3}{1000L}[/tex] = 1.1 kg/LY después convertimos kg en g:
1.1 kg/L * [tex]\frac{1000g}{1kg}[/tex]= 1100 g/LFinalmente dividimos la masa deseada (400 g) entre la densidad, para calcular el volumen:
400 g ÷ 1100 g/L = 0.364 Lwhy is the symbol Ar used in the electron configuration of potassium, and what does it represent?
Answer:
It represents the noble gas that precedes the period before Potassium.
Explanation:
Period before potassium is 3, the noble gas in that period is Ar (Argon). So when condensing the electron configuration of Potassium, Argon can account for 18 electrons instead of writing out 18 electrons in full form from 1s2, 2s2 etc.
You are planning on making punch and you would like to cool it with ice. At the store, there are 2 different one-pound bags of ice to choose from: one that contains large ice cubes one that contains small ice chips. You only want to purchase one bag of ice and will add the entire bag to the punch. Would one of the bags cool the punch at a faster rate? If so, which one and why? If not, why? Would one of the bags of ice cool the punch to a lower temperature? If so, which one and why? If not, why? (Not really a chem q, I didn't know what subject to put it in)
teapot filled with water is heated on the stove. What does the heat from the stove do to the molecule of water in the teapot?
Answer:
The kettle on the stove takes thermal energy from the stove and uses it to convert water into steam at constant temperature. The molecules of water vibrate with increasing speeds when the temperature of water increases. When the temperature of water reaches the boiling point, water starts to change its state to steam.
Explanation:
Qu 4.
How many protons, neutrons, and electrons are present in an atom of gold, Au,
with a mass number of 197?
197 protons, 276 neutrons, 79 electrons
79 protons, 118 neutrons, 79 electrons
Du Do
79 protons, 197 neutrons, 118 electrons
&
118 protons, 72 neutrons, 118 electrons
Answer:
It's the second one down.
Explanation:
Gold
Mass 197
Number of Protons: 79
Number of Neutrons: 197 - 79 = 118
Number of electrons: = number of protons = 97
why sodium and chlorine are active element
13. The quality of petrol as an engine
fuel improves with a higher amount
of
A. branched chain alkanes.
B. branched chain alkenes.
C. branched chain alkynes.
D. straight chain alkynes.
E. straight chain alkynes.
Answer:
The correct option is;
A. Branched chain alkanes
Explanation:
By the process of cracking of petroleum, higher quality petrol are formed by converting straight chain petrol to branched petrol, which are the grade of petrol that burns more smoothly and therefore efficiently within internal combustion engines
The cracking process includes;
a) The conversion of alkanes which are large molecules into branched octanes
b) The conversion of alkanes with straight chain into branched chain alkanes
c) The formation of a branched chain alkane and an alkene from straight chain alkanes
d) The formation of branched chain alkane and hydrogen gas from a straight chain alkane.
Why is a synthetic gemstone (made by humans) not considered a mineral?
Answer:simce it’s manmade, it doesn’t have all the elements it needed if it was natural. It’s basically synthetic or artificial
Explanation:
Displacement can be added to get the total
a) velocity
b) distance
c) speed
d) acceleration
PLEASE HELP, ILL GIVE BRAINLIEST
What is the formula for this molecule? *
Answer:
CNH5 i guess...................
Answer:
CNH5 is the formula.
Explanation:
There is 1 carbon molecule, 1 nitrogen molecule, and 5 hydrogen molecule.
Which of the following would increase the intensity of the tornado?
a. decrease in wind speed
b. decrease in condensation
c. increased rate of evaporation
d. increase of cold air
The tail in figure A and the rings in figure C are held together by a similar force. What force holds the tail and the rings together?
Answer:
It has to be weak vander waal's forces of attraction.
Answer:
The tail and the rings are held together by the force of gravity.
If 0.20 bushel is 1 dozen apples and a dozen apples has a mass of 2.0 kg, what is the mass of 0.50 bushel of apples?
Answer:
Mass of 0.50 bushel = 5 Kg
Explanation:
Given data:
Number of apples in 0.20 bushel = 1 dozen
Mass of 1 dozen apple = 2.0 Kg
Mass of 0.50 bushel apple = ?
Solution:
First of all we will calculate the number of dozen of apple in 0.50 bushel.
(1/0.20) ×0.50 = 2.5 dozen
Mass of 0.50 bushel = 2.5 dozen × 2.0 Kg/1 dozen
Mass of 0.50 bushel = 5 Kg
PLEASEEE HELP FAST!!!! PLEASEEE!!!!!!!
What type of radioactive decay is represented by the arrow?
Alpha
Beta
Gamma
Answer:
beta
Explanation:
PLEASE HELP DUE IN EXACTLY 15 mins!! i will give you branliest
[tex]2032533 \sq22222rt[2]{?} [/tex]
If the current flowing from the supply is 0.12 A, what current will flow through 10 ohms resistor?
Worth 20 points and will mark brainliest!
If the resistor is in series to the voltage supply then 0.12A current will also flow through it.
(How the resistor is placed in relation to the supply is unknown)
Under which conditions of temperature and pressure would a 1-liter sample of a real gas behave most like an ideal gas
Answer:
high temperature and low pressure
Explanation:
An ideal gas is a type of gas which obeys the gas laws at all conditions of pressure and temperature. Whereas a real gas does not obey the gas laws and does not behave according to the kinetic molecular theory.
But a real gas almost behaves like an ideal gas and follow the kinetic molecular theory at a sufficiently high temperature ad low pressure.
1. Solve for x
Atomic number 31
Atomic mass x
Number of protons y
Number of neutrons 33
Number of electrons 28
Charge of element z
Answer:
Atomic mass = proton + neutron
31+33= 64
Number of proton = Atomic number = 31
Charge of element is +3
Explanation:
7. Base your answer to the following question on the information below and on your knowledge of biology A student designed an experiment to investigate a claim that athletes would have lower heart rates than nonathletes during exercise. After the students classified themselves as an athlete or a nonathlete, their resting pulses were determined. Then all the students performed the same exercise for four minutes and their heart rates were determined by recording the pulse rate in beats per minute. The students continued to measure their pulse rates for an additional four minutes. The average heart rate per minute for each group was determined. The data were recorded, as shown on the table below Average Heart Rate Response to Exercise (beats per minute) Time (minutes) Athlete Students Nonathlete Students Resting Pulse 68 72 1 76 78 2 82 90 Exercising Period 3 115 95 110 4 130 5 100 125 6 95 120 After Exercise 7 85 100 8 68 95 2.4 To improve the validity of the conclusion reached in this experiment, the students should repeat the experiment A) disregarding any data that don't fit the hypothesis B) with a larger number of athletes and nonathletes C) comparing the heart rates and breathing rates of males and females D) with the athletes doing different exercises than the nonathletes
Which increases along faults and leads to rock breaking? damage earthquake focus stress
A. damage
B. earthquake
C. focus
D. stress
Answer:
Stress
Explanation:
Stress increases along faults and leads to rock breaking. Therefore option D is correct.
Along faults, stress builds up in the rocks due to the movement and interaction of tectonic plates. Stress is the force applied to the rocks, and it can occur in various forms, such as compression, tension, or shear. As the stress increases, the rocks become more strained and are pushed to their breaking point.
When the stress exceeds the strength of the rocks, they can no longer withstand the applied forces and break, resulting in an earthquake. The release of accumulated stress along the fault causes the rocks to rupture and generate seismic waves, leading to ground shaking and the propagation of energy throughout the Earth's crust.
Therefore, stress is the primary factor that increases along faults and ultimately leads to rock breaking and the occurrence of earthquakes.
Know more about tectonic plates:
https://brainly.com/question/16926233
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Theresa creates an experiment where she mixes two red-colored substances together in a container and observes the solution slowly changing from red to blue for the next eight minutes. The solution becomes completely blue after eight minutes. What does this represent about the type of change happening in the container?
Complete Question:
Theresa creates an experiment where she mixes two red-colored substances together in a container and observes the solution slowly changing from red to blue for the next eight minutes. The solution becomes completely blue after eight minutes. What does this represent about the type of change happening in the container?
Group of answer choices
A. A chemical change started immediately and finished at eight minutes.
B. A non-chemical change started immediately and finished at eight minutes.
C. A chemical change occurred at four minutes.
D. A non-chemical change occurred at four minutes.
Answer:
A. A chemical change started immediately and finished at eight minutes.
Explanation:
A chemical reaction can be defined as the chemical process which typically involves the reaction between two or more chemical elements (substances) to form a new compound, through the rearrangement of the ionic or molecular structure of each chemical element.
This ultimately implies that, a chemical reaction is a chemical change that immediately starts when two or more molecules of a chemical element (substance) known as reactants are combined together to form a new product (compound).
In this scenario, Theresa creates an experiment where she mixes two red-colored substances together in a container and observes the solution slowly changing from red to blue for the next eight minutes. The solution becomes completely blue after eight minutes. Thus, what this represent about the type of change happening in the container is that, a chemical change (from red to blue) started immediately and finished at eight minutes.