Use the image to answer the question
Cassie is working on an investigation for science. She mixes a yellow liquid and a solid chemical in a flask. Which answer best describes her results?
A.
A physical change occurred because the substances kept their properties.
B.
A physical change occurred because the liquid turned yellow.
C.
A chemical change occurred because a gas was formed from a chemical reaction.
D.
A chemical change occurred because the liquid was boiled.
PLEASE HURRY
Answer:
C. A chemical change occurred because a gas was formed from a chemical reaction
Answer:
B A physical change occurred because the liquid turned yellow.
why is
helium number 2 (the second element)
and beryllium number 4 (the fourth
element) on the periodic table ?
Answer:
See note in Explanation
Explanation:
The modern periodic table of the elements is arranged in order of increasing atomic numbers which is also in terms of the number of protons in the nucleus. That is, for any element listed on the periodic table its atomic number equals the number of protons in the nucleus. Thus, the element with 2 protons in its nucleus would be element #2 (Helium), element #3 (Lithium) has 3 protons in its nucleus and element #4 (Beryllium) has an atomic number 4 and contains 4 protons in its nucleus.
Also, this arrangement of elements finds that elements below elements 2, 3 & 4, Neon #10; sodium #11 & magnesium #12 have similar chemical and physical properties as does elements #2, #3 & #4. Such gives rise to the 'Periodic Law' => the chemical and physical properties of the elements is a periodic function of their atomic number (or, number of protons in the nucleus).
help !! Im not sure how to do this
In an experiment, the independent variable __________. (WILL MAKE BRAINLIEST)
A.
always influences the dependent variable
B.
is the same for all groups in an experiment
C.
is influenced by the dependent variable
D.
is manipulated or varied by researchers
Thanks to anyone who helps! :)
Answer:
D
Explanation:
Independent variables (IV): These are the factors or conditions that you manipulate in an experiment. Your hypothesis is that this variable causes a direct effect on the dependent variable. Dependent variables (DV): These are the factor that you observe or measure.
Give below are the four mixtures. Choose the correct one which can be separated by winnowing. (i) soybean and chickpeas (ii) wheat and rice (iii)cotton and cornflakes (iv)Banana wafers and chips Which of these can be separated by the method of winnowing?
Answer:
Banana wafers and chips
Explanation:
Winnowing is the process of separating heavier and lighter components of a mixture by blowing air through the mixture. This implies that the relative weight of the particles in the mixture determines whether they can be separated by winnowing or not.
However, chips are heavier than wafers. wafers refer to a very light snack which is easily blown away by a current of air. Hence banana chips and wafers can be separated using the method of winnowing.
SHOW WORK
A football field is 120.0 yards long, how long is a football field in inches?
Answer:
4320 inches
Explanation:
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The graph indicates the running route for Tobias.
A graph with horizontal axis time (seconds) and vertical axis position in (meters). The line runs in straight segments from 0 seconds 0 meters to 4 seconds 10 meters to 6 seconds 5 meters to 10 seconds 10 meters to 12 seconds 15 meters to 14 seconds 5 meters to 16 seconds 22 meters to to 20 seconds 28 meters.
Which best describes his run?
A.From time 0 to 6, he went fast and then slowed down.
B.From time 6 to 10, he was at his slowest.
C.From time 12 to 14, he went very slow.
D.From time 14 to 18, he went toward the starting point.
Answer: b
Explanation:
Answer:
B
Explanation:
just took the test!!
Find the empirical formula of a
compound which contains 80% carbon
hydrogen by mass
and 20%
Answer:
Element
%
Atomic weight
Percentage at weight
Simple ratio
C
80
12
H
20
1
Hence, empirical formula of hydrocarbon .
Hope it will help you......what happens when washing soda is exposed to the atmosphere
Answer:
they lose their water
Explanation:
When exposed to air washing soda crystals lose their water of crystallisation and become amorphous. ∴ The phenomenon is called efflorescence.
15. A substance that has a melting point of 1074 K
conducts electricity when dissolved in water, but
does not conduct electricity in the solid phase. The
substance is most likely
A) an ionic solid
C) a metallic solid
B) a network solid
D) a molecular solid
Answer:
Ionic solid.
Explanation:
Ionic solid dissociated into free ions capable of conducting electricity in aqueous solution. Ionic solids are also characterised by high melting point due to strong ionic bonds. No free ions or electrons to conduct electricity in solid form.
The substance conducts electricity when dissolved in water, but does not conduct electricity in the solid phase and will be most likely an ionic solid. Therefore, option (A) is correct.
What are ionic solids?Ionic solids can be described as made of lattices of alternating ions. They are not close-packed structures because they like ions would have to touch. Ionic solids are commonly insulators because electrons are tightly held to the ions. They have high melting points due to strong ionic bonds
Due to the strong attractive forces between ions in ionic solids, they have high melting and boiling points. An ionic compound can conduct electricity in water and when it is melted.
In solution, the ions of the ionic solids are free to move and can conduct an electrical charge. The molten state also gives freedom of movement for the ions to conduct while Ionic solids are good insulators.
The ions in the solid cannot move due to the strong attractive forces between oppositely charged ions and, therefore, they do not conduct electricity well.
Learn more about ionic solids, here:
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the _ of an element is the average mass of an element naturally occurring atom, or isotopes,taking into account the _ of each isotopes
Answer:
the atomic mass of an element is the average mass of an element naturally occurring atom, or isotopes, taking into account the percentage of each isotopes
Explanation:
The atomic mass of an element is obtained by obtaining the relative abundances (in percentages) of naturally occurring atoms and the masses of the isotopes. The atomic mass can also be defined as the sum of the protons and the neutrons in the nucleus of an element.
In the periodic table, the atomic mass is indicated below the symbol of each of the elements and is usually in the decimal form.
What forms when two atoms combine?
Answer: A molecule is formed when two or more atoms combine together.
Hope this helps!
√2a-3 =
√a+ 7 solve
Answer:
[tex] \huge100(3 + 2\sqrt{2} )[/tex]
is the right answer.
a light particle has the wavelength of 426.2 nm. what is the wavelength in meters
Answer:
0.0000004262m
Explanation:
i just looked up a converter.
Explain why ammonia is a gas at room temperature
Answer:
Originally Answered: Why is ammonia in gas form at room temperature? That is because ammonia's boiling point is -33.34 Celsius or -28 Fahrenheit. The average household temperature is about 28 to 32 Celsius depending where you live but wherever it is, it is definitely above the boiling point of ammonia.GOOD LESSONS ♡
why one has higher mass and why?
0.5 mole of coz or 16g of sog
so2 has mass of 16gm and co2 has mass
of 22gm. Thus co2 has more mass.
Explanation given in the image.
Hope it helps!
How would you expect this object to behave if it starts out not moving? (The object is the circle, and the arrows show forces acting on the object.) speed up moving to the left speed up moving to the right move to the right at a constant speed move to the left at a constant speed
Answer:
its a
Explanation:
i took the test and its right
The object is the circle, and the arrows show forces acting on the object, speed up moving to the left.
what is speed ?Speed is the ratio of distance to the time in which the distance was covered, it is a scalar quantity as it has only direction and no magnitude.
The speed is represented as s=d/t, Where, s is the speed in m.s-1, d is the distance traveled in m, t is the time taken in s
There are four types of speed such as Uniform speed, Variable speed, Average speed, Instantaneous speed
Uniform speed in which the object covers equal distance at equal time , whereas variable speed is defined as when the object covers a different distance at equal time interval.
Average speed is defined as the uniform speed the ratio of total distance travelled by an object to the total time taken by the object.
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What is the molarity of a solution made by dissolving .75mol of NaCl in 3.0L of solution?
please answerrrrrrrrrrrrrrrrrrrrrrrrr
Answer: I'm in no way like an expert but I've heard water goes from an elevated area to a lower area. So it should be arrows that start at a more elevated to less elevated. Like white to brown, and orange to yellow, and stuff like that. I hope that helped? Anyway, have a lovely day!
Explanation:
What is the mass of sodium (Na) in 50 grams of table salt (NaCl)? Show
your work.
QuesLIVII 2 PUNILS)
Explain the difference between ionic, polar covalent and nonpolar covalent bonds and how
electrons are used in the bond. Use the table below to identify the bond present in the 5
molecules. Show your calculations of the electronegativity difference between elements to
support the identified bond.
Element
Carbon
Nitrogen Sodium Chlorine Magnesium Fluorine Hydrogen
(N)
(Mg) (F) (H)
(Na)
(CI)
Electronegativity
2.5
Value
3.0
0.9
3.0
1.2
4.0
2.1
a) MgCl2
b) F2
c) NaCl
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Answer:
See explanation
Explanation:
An ionic bond involves the transfer of electrons from one atom to another. Typically, ionic bond occurs between a metal and a non metal such as between Na and Cl.
A polar covalent bond occurs between two elements having a significant difference in elctronegativity. As a result of this, the shared electron pair is closer to the more electronegative atom thereby making the molecule polar.
A covalent bond involves the sharing of electrons between two atoms that are very close in electronegativity values. The shared electron pair is located at an equidistant position from the nucleus of the both bonding atoms.
For MgCl2, the electronegativity difference is 3.0 - 1.2 = 1.8, the bond is ionic
For F2, the electronegativity difference is 4.0 -4.0 = 0, it is a pure covalent bond.
For NaCl, the electronegativity difference is 3.0 - 0.9 = 2.1, the bond is ionic
What is the potential energy of a 2 kg rock sitting at the top of a 10 meter high cliff?
Answer:
im sorry im bored can we talk
Explanation:
lol
RESPONSES MUST BE WRITTEN IN YOUR ANSWER PACKET RESPONSES MUST BE WRITTEN IN YOUR ANSWER PACKETESSAY QUESTION:Answer your essay question in space below 20ptsHow are the key elements of scientific thinking used in the following scenario?(Use 3+ specific examples)While you are heating water in an electric kettle, you notice it fails to boil water. Thinking that some part of the kettle (coil or cord etc.) is malfunctioning, you notice there is no change in the water temperature. Assuming you forgot to plug the kettle in, you check and discover it is plugged into the wall (outlet). You then take the kettle to a different room and try plugging it into a different outlet – you find the kettle works. You conclude that there is no power in the kitchen. Coming back to the kitchen, you turn on the light and find that nothing happens.
Answer:
i mzxd vsdfvdsfbdfdf
Explanation:
Answer:
i dont get it
Explanation:
Question 5(Multiple Choice Worth 5 points)
Two samples of water, 10 grams and 50 grams, are in separate cups. Which of the following properties is different for the two?
O Boiling point
O Color
O Density
O Volume
Answer:
Density
Explanation:
Answer: the answer is density
Explanation:
A chemical equation is shown:
C2H4 + O2 → CO2 + H2O
According to the law of conservation of mass, how many atoms of oxygen exist in the products of this reaction? (3 points)
Answer:
Explanation:
C2H4 + O2 → CO2 + H2O
eqn is unbalanced - balancing by counting no. of C n H atoms
C=2 n H=4 in one C2H4
so the reaction will form two CO2 + two H2O
counting no. of O atoms: 2*2 + 2*1
=4+2
Answer:6
Explanation:
The force that keeps the planets in orbit is________.
Question options:
mass
gravity
friction
kinetics
Answer:
The force that keeps the planets in orbit is gravity.
3) Which element is the 2s orbital closest to the nucleus?
A) Te
B) Se
C) O
D) Po
E)S
give 3 importance of learning about fault
Answer:
These breaks, across which slip has occurred, are called faults. ... So understanding the types and patterns of ancient fault can help geologists to ... The faulting patterns can have enormous economic importance
Calculate the energy of a photon with a frequency of 3.20 x 10^-11 s^-1
Answer:
E = 21.22×10⁻⁴⁵ J
Explanation:
Given data:
Frequency of photon = 3.20×10⁻¹¹ s⁻¹
Energy of photon = ?
Solution:
Formula:
E = h×f
h = plancks constant = 6.63×10⁻³⁴ Js
by putting values,
E = 6.63×10⁻³⁴ Js × 3.20×10⁻¹¹ s⁻¹
E = 21.22×10⁻⁴⁵ J
What is the mass of 2.2 moles of Beryllium chloride
Answer:
the mass of 2.2 moles of Beryllium chloride is
Explanation:
175.8200004 gram