Which two observations are evidence that a chemical change is happening?
A. A yellow liquid forms as a yellow solid is slowly heated.
I B. Bubbles of gas are released when a solid is combined with a
liquid.
I c. Solid crystals form as the temperature of a liquid is lowered.
D. Light and heat are given off after a spark ignites a substance,

Answers

Answer 1
B. Bubbles are created whether using heat or not at inception of chemical change

Related Questions

A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?
The sodium ion is positive, and the hydroxide ion is negative.
The sodium ion is neutral, and the hydroxide ion is neutral
ОООО
The sodium ion is positive, and the hydroxide ion is

Answers

Answer:

PLEASE DO IT PROPERLY I WELL ANSWER IT BUT I CAN'T "I CANNOT UNDERSTAND" I'M VERY SORRY

Explanation:

Question:A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?

A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.

A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.The sodium ion is neutral, and the hydroxide ion is neutral

A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.The sodium ion is neutral, and the hydroxide ion is neutralОООО

A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.The sodium ion is neutral, and the hydroxide ion is neutralООООThe sodium ion is positive, and the hydroxide ion is

Answer:The litmus paper test is a simple test in order to determine whether a given solution is acidic or basic. One will have to place a drop of a solution on the litmus paper. If it changes a red litmus paper to blue, the solution is basic. If it changes a blue litmus paper to red, the solution is acidic.

the are 2 answers

2nd² answer:It's because of 7-hydroxyphenoxazone. When exposed to acids below pH 4.5, the molecule looks like the image below and this gives litmus paper its red color. As the pH of the test solution moves towards alkaline, one of the hydrogen atoms (white hemispheres) starts to break off (disassociate).

CARRY ON LEARNING

THANKS FOR THE POINTS I HOPE YOU'LL UNDERSTAND ME.

P I E C K N P I E C K __________________

PLEASE DON'T PUT ANSWER AGAINST GUIDELINES!!!

Answers

Answer:

160.3 g S

Explanation: there you go

Is mercury an electrolyte at room temperature?​

Answers

Answer:

No

Explanation:

Despite mercury being a metal, it is a liquid at room temperature. It cannot be an electrolyte. This is because most of the liquids that can conduct electricity or acids bases and salts whereas mercury is a metal.

no, mercury is a liquid at room temperature it is a metal. it cannot be an electrolyte

What is the mass number (A) of an atom that has an atomic number (Z=26) with 29 neutrons and 26 electrons?​

Answers

Answer:

A = 55

Explanation:

The atomic number is the number of protons also = the number of electrons, so basically we have 29 neutrons, 26 electrons and 26 protons. Anyway, it's asking the mass number which is the neutrons + the protons, so you just take 29+26 = 55

Atomic number=26

Neutrons=29

Electrons=26

Mass number=Proton+neutron

Protons=26

Mass number=26+29

=55

This is my class group-work with my friends but we are stuck on this question.

Answers

Explanation:

It has to be C, because Carbon can bond with four other atoms and is like a four-hole wheel.

(Sorry if my elplanation was kinds choppy Oof, helpfully it makes sense?)

Why does atomic radii decrease as you move from the left to right across the period

Answers

Answer:

This is because, within a period or family of elements, all electrons are added to the same shell.

When we move from left to right across the periodic table, we can see that the atomic radii keeps decreasing. This is because, as you move from left to right, the nucleus gains protons. The atomic number increases and hence the valence electron will feel more attracted towards the nucleus & the atomic radii will decrease.

[tex]\mathbb{MIREU}[/tex]

If a sample of gas at constant temperature has its pressure doubled, what will happen to its volume?

Answers

Answer:

it'll halve

Explanation:

the gas is compressed with twice the pressure. The volume will be halved.

im certain

Different isotopes of an element have different numbers of:

Answers

Explanation:

Different isotopes of an element have different numbers of mass number

explain why almunium is often used for long distance over head electric cables (high voltage)​

Answers

Answer:

because it does not cost much and can be found easily.  due to their low resistance and excellent conductivity.

Explanation:

Multiply or divide to find the equivalent fraction.

51/120=□/360

Answers

Answer

153

Explanation:

51/120 = x/360

51(360) = 120x

18360 = 120x

18360/120x = 120x/120x

153 = x

Answer:

153

Explanation:

A molecular compound is found to consist of30.4% nitrogen and 69.6% oxygen. Ifthe molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule

Answers

Answer:

92.01 g/mol

Explanation:

So first you need to find the empirical formula by the percents. That would be, assuming that you have 100 grams of the the sample, divide each quantity of each element found by its respective molar mass.

30.4 g of N ÷ 14 g/mol N= 2.17 mol of N

69.6 g of O ÷ 16g/mol= 4.35 mol of O

You can establish now the empirical formula.

N2.17O4.35,

but since you can't have a decimal subscript, you divide each subscript by the minimum subscript

NO2

So then you're said that the molecular formula derived from that empirical formula has 2 nitrogen, so you multiply all the subscripts, by 2:

N2O4

-Dinitrogen Tetraoxide

-Nitrogen oxide (IV)

Then all you have to do is find the molecular mass of the compound using the periodic table and what you obtain is the molar mass.

remember: molecular mass is correspondent to molar mass.

Part A
What question is being asked through this scientific investigation?
(I didn’t know what subject so sorry, also only answer if u have an answer.)

Answers

pretty sure it’s to see whether carbon dioxide is formed in each bottle so if it does form then the balloon would expand

Answer:

How will the ingredients effect the fermentation of each bottle? What will happen to the bottles and balloons when fermentation occurs?

Explanation:

How many moles is 2.50 grams of oxygen?

Answers

Answer:

Mole is a number that connects mass of a substance with its number of particles. 2500 g of O2 = 1/32 x 2500 = 78.125 moles

Explanation:

have a great day

Which of the following compounds will have the highest boiling point?


MgCl2



CO2


C12H22O12

,

H2O

Answers

MgC12 has the highest boiling point

people tint their car windows to stop what

Answers

Answer:

Reflection

Explanation:

Answer:

b

Explanation:

Alkaline batteries adopted their name from the _____ that is present in the reactions at both the zinc anode and the MnO2 cathode.

Answers

Answer:

hydroxide ion

Explanation:

The alkaline battery got this name because it has an alkaline electrolyte of potassium hydroxide.

name a metal and non metal which are liquid at normal pressure and temperature

Answers

Answer:

metal : Mercury(Hg)

non metal : bromine (Br)

Explanation:

mercury is liquid at room temperature and pressure and the same as bromine

Read this sentence from Chapter One of Jack London’s The Call of the Wild.

Buck rushed at the splintering wood, sinking his teeth into it, surging and wrestling with it. Wherever the hatchet fell on the outside, he was there on the inside, snarling and growling, as furiously anxious to get out as the man in the red sweater was calmly intent on getting him out.

What is a good prediction question to ask after reading this excerpt?

Answers

Answer:

b)

Explanation:

It shows the natrual proggresion of a story and helps blend the narrtive together.

Answer:B

Explanation: i took the quiz on edge

what is the speed of a skater who travels a distance of 210 m in a time of 10 seconds

Answers

Answer:

Speed =d/t. 200÷10=21÷1000=0.021 km/h

Explanation:

S=D/T

SEP Construct Explanations You can see a cloud of your breath outside
on a cold day but not on a warm day. What do you think is happening to
pour breath in the cold air

Answers

Answer:

it because of cold weather

Elements that become cations during bonding become smaller as a result.
A.
True

B.
False

Answers

It’s False sorry if it’s wrong but I hope it help

how many grams are in 4.07x10^15 molecules of calcium hydroxide

Answers

There are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.

HOW TO CALCULATE MASS:

The mass of a substance can be calculated by multiplying the number of moles in the substance by its molecular mass.

However, given that the number of molecules in calcium hydroxide is 4.07 x 10¹⁵molecules, we need to calculate the number of moles in Ca(OH)2 as follows:

no. of moles of Ca(OH)2 = 4.07 x 10¹⁵ ÷ 6.02 × 10²³

no. of moles = 0.676 × 10-⁸

no. of moles = 6.76 × 10-⁹ moles.

Molar mass of Ca(OH)2 = 74.093 g/mol

Mass of Ca(OH)2 = 74.093 × 6.76 × 10-⁹ moles

Mass = 5.01 × 10-⁷grams.

Therefore, there are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.

Learn more about how to calculate mass at: https://brainly.com/question/8101390?referrer=searchResults

Write a balanced equation and name the products of the reaction CaCl2+Na3(PO4)

Answers

Answer:

3CaCl2 + 2Na3(PO4) → Ca3(PO4)2 + 6NaCl

Explanation:

DOUBLE REPLACEMENT REACTION

CaCl2 + Na3(PO4) → Ca3(PO4)2 + NaCl

3CaCl2 + 2Na3(PO4) → Ca3(PO4)2 + 6NaCl

calcium chloride + sodium phosphate → calcium phosphate + sodium chloride

Hope that helps

the atomic number is the same as the number of which subatomic particle?

Answers

Protons, hope this helps

how to tell if something is a strong or weak acid or base

Answers

Answer:

It basically depends upon the pH value of that acid or Base. That's how you can determine whether the substance is a strong or weak acid/base. We have a pH scale ranging from 1 to 14, where 7 is the neutral point. Any substance having a pH of 7 means it is neither an acid nor a Base, but neutral in nature, such as water([tex]H_{2}O[/tex]). Now, if the pH is less than 7, the substance is an acid, similarly if the pH is more than 7, it is a base. As the pH DECREASES, the substance becomes more acidic, on the other hand as the pH INCREASES, the substance becomes more basic. This way you can compare between pH values of two substances and tell which one is stronger or weaker.

For Acids:

If a substance's pH is between 1 and 7 it is an acid. If it is more towards 1, it's a strong acid and if it's more towards 7 it is a weak acid.

For Bases:

If a substance's pH is between 7 and 14 it is a base. If it is more towards 14, it's a strong base and if it's more towards 7 it is a weak base.

Hope that helps...

How does thermal energy flow?

Answers

Answer:

Thermal energy typically flows from a warmer material to a cooler material.

Explanation:

noble gases are used in many situations where a safe and constant environment must be maintained. for example, helium is used to provide a protective atmosphere for making fiber optics and semiconductors. argon is used to fill incandescent and flourescent light bulbs to prevent oxygen from corroding the hot filament. why are noble gases used in these situations?

Answers

Answer:

Noble gases have a complete valence electron shell making them stable and nonreactive.

Explanation:

for the reaction, Pb(no3)2 + 2kI yields pbi 2 + 2 kno3, how many moles of lead iodine are produced from 300 g of potassium iodine

Answers

Good its true no problem plus 222-333

Look at the graph. Which part of the line shows a time
when the object was not moving?

Answers

B.

For the period of B, the line didn’t go up or down, it stayed still.
this shows that time was still passing but the car didn’t move.

A container that can't expand, may explode from the ________ in pressure.

Answers

Increased force ....
Other Questions
I will give as many points just please do this Step 1: Gather materials and necessary information.a) Review the research sites provided in each section.b) Ask your teacher whether you will be using presentation, drawing, or artistic software to develop the map, or if you will be downloading, printing, and then completing your map before scanning it into the computer.Step 2: Read and follow each set of instructions carefully before you begin.a) Follow all instructions for labeling your map.b) Use drawing software (if making an electronic version) or colored pencils (if you have downloaded and printed your map) to color the map as instructed.c) Complete the questions on the research page.Step 3: Create a map of Europe in 1914.a) Download and print out the blank map worksheet included in this document. If you will be using drawing software, copy and save the blank maps in the appropriate program.b) Label these countries: Great Britain (also called the United Kingdom), France, Germany, Austria-Hungary, Italy, Russia, Belgium, Bulgaria, Denmark, Greece, Norway, the Netherlands, the Ottoman Empire, Portugal, Spain, Romania, Serbia, Sweden, and Switzerland.c) Label the Atlantic Ocean, the Mediterranean Sea, the Baltic Sea, the Black Sea, and the North Sea.d) Draw the western front in red.e) Color bodies of water blue.f) Color the countries of the Central powers in one color, the Allied powers in a second color, and neutral colors in a third.g) Add a compass rose.h) Create a key for your map.Step 4: Create a map of Europe after World War I.a) Label these countries: Albania, Austria, Belgium, Bulgaria, Czechoslovakia, Denmark, Estonia, Finland, France, Germany, Great Britain, Greece, Hungary, Italy, Latvia, Lithuania, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, Turkey, the Soviet Union (formerly Russia), and Yugoslavia.b) Label the Atlantic Ocean, the Mediterranean Sea, the Baltic Sea, the Black Sea, and the North Sea.c) Color bodies of water blue.d) Color in green the territory held by the German Empire in 1914.e) Color in orange the territory held by Austria-Hungary in 1914.f) Color in purple the territory held by Russia in 1914.g) Color in brown the territory held by the Ottoman Empire in 1914.h) Outline the newly created countries in red.i) Add a compass rose.j) Create a key for your map. 100 POINTS ANSWER FASTWhich of the following is a contrast conjunction?a.by contrastc.butb.yetd.all of the abovePlease select the best answer from the choices providedABCD It takes about 38 m3 of boards and plywood to build an average-size, single-family home. Can an average-size, single-family home be built with one days output from the saw mill? About how many days will it take for the saw mill to produce enough lumber to build a neighborhood of 100 average-size homes? (d)Given that the fifth and the seventh terms of the G.P form the first two consecutive terms of an arithmetic sequence, calculate the sum of the first 20 terms of the sequence Which of the following expressions is equivalent to. Please help me with this!!! I will mark brainlist!!! Directions: Name the coefficient (s) in the following expressions:1. 9s + 4t2. 46rs + 10x3. 18q + 14x4. 10x + 14y5. 17rs + 32x6. 5x + 7y - 5z7. 3ab + 70m8. 3r + 20a + 10m9. 7k + 16m10. 7r + 5s11. 9j + 120m12. 12k + m13. 6c + 15h + w14. 2c - 19d + 12f15. 3t + 14r - 31jcan someone just answer god Explain whether the pairing is a function 39 round to the nearest hundred What are the compounds that you can find in mayonnaise A solid object where the radius of bse is 7cm and height is 12cm Amare runs 1\10 mile in 2\3 minute. What is his speed in miles per minute? Show your work Find the slope of the line passing through the points A(-2,2) and B(7, -3) what is the meaning of enhanced Malcom and his sister ran 3 races. Their distances are shown below.Race Malcom's / Sister Distance 1. 10 yards 300 inches 2. 18 feet 180 inches 3. 120 inches 5 feet Who can run the farthest? How do you know? Use the lines and space below toprove your answer. What is Plumer's concern about a tie in the Electoral College? Why does he think this would be a bad outcome? Read this lines from Dream Variations by Langston Hughes Then rest at cool evening Beneath a tall tree While night comes on gently,Dark like me-what do these lines suggest?(Options in the pictures) I need help please is important :((( Can someone plz help me? :( 10/11 x 3/7 x 1/2 Multiply. Write your answer as a fraction in the simplest form.