Flammable materials, like alcohol, should never be dispensed or used near Group of answer choices an open door. a sink. another student. an open flame.

Answer:

9 protons 9 electrons and 10 neutron

Explanation:

The atomic number is the number of protons .In a neutral atom,the number of electrons equals the number of protons.Mass number is the sum of the protons and nuetrons of a particular isotope.If you have mass number and atomic number,subtract the atomic number from the mass number to get the number of nuetrons. Mass number- atomic number= number of nuetrons

Answer:

72000 seconds equals 20 hours.

Explanation:

Answer:

b

Explanation:

just got done with this one

Answer:

1.346 g/mL

Explanation:

The density is defined as the mass of a substance per unit of volume.

In the problem, you add 10.0mL of glycerine. the mass change from 78.32g to 91.78g. The difference is the mass of the glycerine:

Mass glycerine: 91.78g - 78.32g = 13.46g

As the volume added was 10.0mL, the density, δ, in g/mL is:

δ =13.46g / 10.0mL =

12.electrons

13.13

14.aluminum has 14 neutron.

Answer :Matter makes up everything visible in the known universe, from porta-potties to supernovas. And because matter is never created or destroyed, it cycles through our world. Atoms that were in a dinosaur millions of years ago—and in a star billions of years before that—may be inside you today.     To form water, however, hydrogen and oxygen atoms must undergo chemical changes. For a chemical change to occur, atoms must either break bonds and/or form bonds. The addition or subtraction of matomic bonds changes the chemical properties of the substances involved. Both hydrogen and oxygen are diatomic—they exist naturally as bonded pairs (H2 and O2, respectively). In the right conditions, and with enough energy, these diatomic bonds will break and the atoms will join to form H2O (water). Chemists write out this chemical reaction as:

2H2 + O2 → 2H2O

This equation says that it takes two molecules of hydrogen and one molecule of oxygen to form two molecules of water. Notice that there are the same number of hydrogen atoms and oxygen atoms on either side of the equation. In chemical changes, just as in physical changes, matter is conserved. The difference in this case is that the substances before and after the change have different physical and chemical properties. Hydrogen and oxygen are gases at standard temperature and pressure, whereas water is a colorless, odorless liquid.  

Ecosystems have many chemical and physical changes happening all at once, and matter is conserved in each and every one—no exceptions. Consider a stream flowing through a canyon—how many chemical and physical changes are happening at any given moment?

First, let’s consider the water. For many canyon streams, the water comes from higher elevations and originates as snow. Of course that’s not where the water began—it’s been cycled all over the world since Earth first had water. But in the context of the canyon stream, it began in the mountains as snow. The snow must undergo a physical change—melting—to join the stream. As the liquid water flows through the canyon, it may evaporate (another physical change) into water vapor. Water gives a very clear example of how matter cycles through our world, frequently changing form but never disappearing.

Light energy allows these bonds to break and reform to produce sugar and oxygen, as shown in the chemical equation for photosynthesis:

6CO2 + 6H2O + light → C6H12O6 (sugar)+ 6O2  

This equation says that six carbon dioxide molecules combine with six water molecules to form one sugar molecule and six molecules of oxygen. If you added up all the carbon, hydrogen, and oxygen atoms on either side of the equation, the sums would be equal; matter is conserved in this chemical change.

When animals in and around the stream eat these plants, their bodies use the stored chemical energy to power their cells and move around. They use the nutrients in their food to grow and repair their bodies—the atoms for new cells must come from somewhere. Any food that enters an animal’s body must either leave its body or become part of it; no atoms are destroyed or created.

Matter is also conserved during physical and chemical changes in the rock cycle. As a stream carves deeper into a canyon, the rocks of the canyon floor don’t disappear. They’re eroded by the stream and carried off in small bits called sediments. These sediments may settle at the bottom of a lake or pond at the end of the stream, building up in layers over time. The weight of each additional layer compacts the layers beneath it, eventually adding so much pressure that new sedimentary rock forms. This is a physical change for the rock, but with the right conditions the rock may chemically change too. In either case, the matter in the rock is conserved.

The bottom line is: Matter cycles through the universe in many different forms. In any physical or chemical change, matter doesn’t appear or disappear. Atoms created in the stars (a very, very long time ago) make up every living and nonliving thing on Earth—even you. It’s impossible to know how far and through what forms your atoms traveled to make you. And it’s impossible to know where they will end up next.  This isn’t the whole story of matter, however, it’s the story of visible matter. Scientists have learned that about 25 percent of the universe’s mass consists of dark matter—matter that cannot be seen but can be detected through its gravitational effects. The exact nature of dark matter has yet to be determined. Another 70 percent of the universe is an even more mysterious component called dark energy, which acts counter to gravity. So “normal” matter makes up, at most, five percent of the universe.

Explanation:

Answer:

This question lacks options, but the question can be answered based on knowledge of proton, electron and neutron number. The answer is:

62 Ni2+ particle

Explanation:

Nickel is a chemical element with atomic number 28. This means it has 28 electrons and 28 protons in its neutral atom. However, the isotope of nickel being described in the question has a mass number of 62. The mass number is calculated by adding the proton number with the neutron number. That is;

Mass number = number of protons + number of neutrons

Mass number = 28 + 34

Mass no. = 62

An element with mass number 62, which has lost two electrons to become positively charged (two positive charges) is described in the question. Hence, the particle that best fits this description is positively charged Nickel particle (Ni2+).

Ni2+ has 28 protons, 26 electrons (reduced by 2) and 34 electrons.

Note that, the 2+ charge is as a result of the loss of two electrons, hence, reducing the electron number by 2.

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass of block = 5 g

volume = 15 mL

The density of the block is

[tex]density = \frac{5}{15} = \frac{1}{3} \\ = 0.33333333...[/tex]

We have the final answer as

The block will float on water since it's density is less than that of water which is 1 g/mL

Hope this helps you

Answer:

The remaining negative electron number is 0.

Explanation:

1 - 1 = 0 since hydrogen has exactly 1 electron. The charge must be balanced if it is a neutral atom. The 1 electron got peeled off and the remaining number is 0. That means the hydrogen atom is a proton now.

Answer:

Barium oxide, BaO, baria, is a white hygroscopic non-flammable compound

Explanation:

so the answer is BARIUM

Answer:

B. normal force

Explanation:

When a cup is placed on a table, the forces acting on the cup are the gravitational force and the normal force. The gravitational force acts in the downward direction while the normal force acts in an upward direction. It is clear that the gravitational force is balanced by the normal force. So, the correct option is (b) " normal force ".

Note that all detail explanation on why or how will be attached at the end

Step 1: Removing the Oil

Theoretically, step 1 and 2 can be alternated and preferably I would start with step 2, but I thought of one first. I would begin by setting up the liquid mixture in a funnel with a closed twist valve. Once the water mixture and oil has separated, I would slowly remove all the water, leaving the oil.

Step 2: Removing the Gravel and Sand

The second step is to filter out solids by using a sand filter. This filter is made by using a Styrofoam cup that has had small holes punched into the bottom with an open paperclip. The cup is filled with layers of clean washed gravel. The gravel will be layered by putting course gravel in the bottom and fine sand in the middle followed by course sand on the top. The gravel on the bottom stops the loss of sand out of the holes and the gravel on top stops the sand from washing out as a sample is poured.

Step 3: Removing the Coffee Grounds and Garlic Powder

You would start by lining a clean funnel with a coffee filter or something comparable. Then, you would add a spoonful or so of Charcoal to the funnel. Then you would pour the mixture of water, garlic powder, salt and coffee grounds into it.

Step 4: Removing Salt

You would preform a simple evaporation to remove the salt from the water. If the water is still needed, then you can preform a sealed distillation which has the same effect, but just keeps the water.

Step 5: Celebrate!

If you are doing this is a school, congratulations! you just finished your assignment/lab! If you are doing this in the wilderness for survival, congratulations! you won't die so soon!*

*The purification of water will not guarantee your extended survival in the wilderness, just extend the time in which you will not die of dehydration.™

Explanation:

Step 1 works because the density of oil and water are different, so as you let the liquid settle, the two liquids will separate into two sections. This allows you to funnel the water out. Step 2 work because the gravel and sand you want out cannot pass the sand-gravel filter you made (as long as it was made correctly) Step 3 works because the garlic powder and coffee grounds cannot pass the filter and the smell and colour that leaked into the water would be removed by the charcoal. Step 4 works because as water evaporates or is boiled off, the salt cannot evaporate with it, so it is left behind. Like how I was in the mall. Step 5 works because this was a long explanation and now you can go look at memes.

Answer:

The answer is

Explanation:

The acceleration of an object given it's mass and it's net force can be found by using the formula

[tex]acceleration = \frac{force}{mass} \\ [/tex]

From the question

force = 60 N

mass = 12 kg

So we have

[tex]acceleration = \frac{60}{12} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

Explanation:

Because different isotopes have different numbers of neutrons, they do not all weigh the same or have the same mass. Different isotopes of the same element have the same atomic number. They have the same number of protons. The atomic number is decided by the number of protons.

Answer:

Because different isotopes have different numbers of neutrons, they do not all weigh the same or have the same mass. Different isotopes of the same element have the same atomic number. They have the same number of protons. The atomic number is decided by the number of protons.

Answer:

Mass of Ca in sample, Mass of Br in sample, Number of moles of Ca in sample, Number of moles of Br in sample, Mass or moles of element other than Ca or Br in sample

Explanation:

The AP Classroom will not count your answer to this question as correct unless it includes at least one of the answers listed above. If you say that theanswer to this question is density, it will be marked as incorrect, I found that out the hard way when I used the answers that brainly gave me.

Good luck,

I applaud you for using the sources avalible to you, which is /definetly not/ cheeting.

Answer: A, C, E

Explanation: PLATO. all testable questions.

Answer:

1000 gram

Explanation:

because mass is constant everywhere

Answer:

[Ar] 3d⁸ 4s²

Explanation:

Atomic number: 28

Symbol: Ni

Atomic mass: 58.6934 u

Answer:

brittle is not a characteristic of medals.

Answer:

Matter can be classified according to physical and chemical properties. Matter is anything that occupies space and has mass. The three states of matter are solid, liquid, and gas. A physical change involves the conversion of a substance from one state of matter to another, without changing its chemical composition.

Explanation:

You omitted what it was raised to the power in 1.3 x 10's gallons of water,  so i will put it up as   1.3 x 10^15 gallons of water and solve with it

Answer:1,083,333 days

Explanation:

Total amount of water held by lake Michigan= 1.3 x 10^15 gallons of water

Amount of water Chicago uses per day =Chicago uses 1.2 x 10^9 gallons of water /day

Therefore,

Number of days water would last if it doesnt rain =  Total gallons provided by lake Michigan/ Total gallons consumed per day

=1.3 x 10^15 gallons of water/ 1.2 x 10^9 gallons of water /day

= 1,083,333 days

Answer:1.0243

Explanation: I think that is it

The answer is B aka 1.0250 :)

Answer: 3.240576

Explanation:

There are various ways of doing multiplication this is one of them

The wording "keep in mind the rules for significant digits" implies that we are to use these to show where the decimal place goes by approximating the answer. Then conducting the exact calculation.

Consider 0.8 as 8  

×

1

10

3

×

8

×

1

10

=

2.4

So the solution is some where a bit above 2.4

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Lets just use the numbers

Multiply both 0.8439 and 3.84 by 1000 to get rid of the decimal place. This makes thing more straight forward. So we end up with:

8439

×

38400

Split up the 38400 into 30000+ 8000 + 400

30000

×

8439

=

253170000

.

8000

×

8439

=

.

67512000

.

.

400

×

8439

=

.

.

3375600

−−−−−−−−−  

←

Add

.

324057600

By our approximation we are expecting the form of

2.4

+

small amount

So the answer is  

3.240576

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Check by calculator:  

0.8439

×

3.84

=

3.240576

Answer:

1 18 grams

2 500g

4 960 grams

5 7 kilograms