Which best describes an element?
a pure substance
a type of a mixture
a pure compound
an impure substance

Answers

Answer 1
An element is a pure substance
Answer 2

Answer:

An impure substance

Explanation:

Substance means: hard surface example: salt,corals,coal.


Related Questions

Elements are usually dull, brittle and do not conduct electricity are know as_____.

Points: 46

Answers

Answer:

nonmetals. it's one of them

A sample of gas occupies 20 mL at -109 degree C. What volume does the sample
occupy at 65 °C?

Answers

Answer: V2= 41.2mL

Explanation:

Givens:

* V1= 20ml

* T1 = -109 ⁰C --> K= ⁰C + 273.15 --> 164.15 K

* V2 = ??

* T2= 338.15 K

Use Charles law V1/T1 = V2/T2

Since we are looking for V2 we can rearrange the formula to

V2= (T2 x V1) /T1

V2= (338.15K x 20mL) / 164.15 K

V2= 41.2mL

NOTE:

Temperature should always be in K not in ⁰C or ⁰F

To convert from C to K use

*K= ⁰C + 273.15

Enter your C value in the ( ⁰C ) and you can get K

Why is eating animals to obtain energy considered exothermic

Answers

Its considered exothermic because it helps then stay cool or and hot

What is the number of atoms of oxygen in 0.1 mol of CuSO4.5H2O? & explain​

Answers

0ne mole of CuSO4.5H2O contains 6.023×10^23 no.of molecules

Again, 1 mole CuSO4.5H2O contains 9 oxygen atoms

Therefore,1 mole CuSO4.5H2O contains 9 × 6.023×10^23 no.of oxygen atoms

Hope this help!

Help!! I’ll mark you Brainliest.!

Answers

Answer:

For 5 pts? gimme that

Explanation:

Answer:

Explanation:

if you know what those phrases mean, then you can look them up and draw those pictures you find, as well as add the definition of each.

Pls help I will give u points pls

Answers

Answer:

i think D

Explanation:

The last layer in layered design is _____________. Object Process None of the options Atoms Sub process

Answers

The last layer in the layered design is system layer so none of the above is the correct option.

Robotic Process Automation is a software technology that make use of some programs of computer to copy or mimic the behaviors of human when it has access with them. They been use effectively and ensure the work is perfectly done.

There are layers in the Robotic process automation but the last layer is System layer.

They can handle high volume of tasks.

The lowermost layer is associated with individual screen interactions. The lowermost layer in the layered design of Robotic process automation is the component layer or system layer . The Robotic Process Automation and this form technology is in robots creation.

Therefore, The last layer in layered design Is System layer so none of the above is the correct option.

Learn more about Robotic process automation from the link below.

https://brainly.com/question/41671370

NO LINKS!!!

Static electricity is a ____ charge.
A. permanent
B. missing
C. flowing
D. temporary

Answers

Hey there!

Static electricity is a missing charge. When positive ions are formed (where an electron is missing), this imbalance is called static electricity.

Answer: Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it is able to move away by means of an electric current or electrical discharge.

will give brainlist to a person with correct answers for all (please help me)
1. Explain how is LiCl formed?
2. What is a combination/synthesis reaction
3. What is a decomposition reaction?
4. What is a single-replacement reaction?
5. What is a double-replacement reaction?
6. What are the trends in electronegativity within groups and across periods in the periodic table?
7. Which element has the lowest electronegativity value?
8. How does electronegativity determine the type of bond that atoms will form?
9. What type of bond will form between 2 atoms that have a large difference in electronegativity?
10. What type of bond will form between 2 atoms when the difference in electronegativity is 0.5?
11. Which element has the highest electronegativity value?
12. What does it mean that matter cannot be created nor destroyed in a Chemical reaction?

Answers

Answer:

1. LiCi is formed by the treatment of lithium carbonate with hydrochloric acid

2. A combination reaction (also known as a synthesis reaction) is a reaction where two or more elements or compounds (reactants) combine to form a single compound (product).  

3. Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity into two or more fragments.

4. A single-displacement reaction, also known as single replacement reaction or exchange reaction, is a chemical reaction in which one element is replaced by another in a compound

5. Double replacement reactions have two ionic compounds that are exchanging anions or cations.

6. The most electronegative elements are found on the top right of the periodic table.

7. cesium

8. Electronegativity describes the degree to which an atom attracts electrons in a chemical bond. But the electronegativity of two atoms would determine their bond type.

9. ionic bond

10. polar covalent bond

11. fluorine

12. Matter can change form through physical and chemical changes, but through any of these changes, matter is conserved. The same amount of matter exists before and after the change.

Hope i was able to help!!!

what are the relationships among bond order, bond length, and bond energy?

Answers

Explanation:

When a bond is strong, there is a higher bond energy because it takes more energy to break a strong bond. This correlates with bond order and bond length. When the bond order is higher, bond length is shorter, and the shorter the bond length the greater the bond energy.

how do the densities of crystalline and amorphous polymers of the same material that have identical molecular weights compare?

Answers

Answer: The density of a crystalline polymer is greater than an amorphous polymer of the same material and having the same molecular weight.Hope i help you! ❤️


Find the actual yield when the theatrical yield is 1.09g and percent yield is 90%.​

Answers

Actual yield/Theoretical yield *100= Percentage yield. So Actual yield = Percentage yield*Theoretical yield.
Therefore actual yield= 90/100 * 1.09g = 0.98g

Actual yield: 0.98 g

Alison observes that when she injects additional gas molecules into a container of gas, the number of collisions in the container (and the pressure inside) increases. She then increases the volume of the container just enough to restore it to its original pressure. Which of the following laws best describes what Alison observed?
A. Amonton's Law
B. Avogadro's Law
C. Boyles Law
D. Charles's Law
E. Dalton's Law

Answers

Answer:

Explanait it is not d

If two atoms have an electronegativity difference of 1.3, what type of bond would form between them?
Select one:a. non polar covalent b. polar covalent. c. ionic​

Answers

Answer:

I would say iconic bond

Explanation:

Answer:
b. polar covalent
Explanation:
any electronegativity difference between .6 and 1.7 is polar covalent and anything greater than 1.7 is ionic, since this is less that 1.7 and greater than .6 the bond is polar covalent
Hope this helps!

Which element has a greater Ist ionization energy, Phosphorus or Fluorine?

Answers

Answer:

phosphorus

Explanation:

i believe it’s fluorine (?)

Choose the best answer.
What is the sum?
2/3+7/15
O 14/15
O1/2
O1 2/15
O3/5

Answers

Answer:

1 2/15

Explanation:

2/3 + 7/15 = 17/15 =1 2/15

When Brian first sorted out his thoughts, he figured this was the first day after the crash and what did he think would happen next?​

Answers

It should be noted that when Brian first sorted out his thoughts, the first thing that he thought would happen next is that he would probably be rescued that day.

It should be noted that in Chapter 5 of Hatchet, Brian wakes up in the forest and then, he realized that he was desperately thirsty.

When Brian first sorted out his thoughts, he figured this was the first day after the crash and that he would probably be rescued that day. He believed that he was going to wither up and die if he doesn't get anything that he'll drink.

Learn more about excerpts on:

https://brainly.com/question/21400963

002 (part 1 of 2) 10.0 points
1.5 mol HCl and 3.7 mol NaOH react accord-
ing to the equation
HCl + NaOH → NaCl + H2O.
If the limiting reactant is HCl, calculate the
amount of NaCl formed.
1. 1.9
2. 2
3. 1.1
4. 1.5
5. 1
6. 1.8
7. 1.2
8. 1.3
9. 1.4
10. 1.7
Answer in units of mol.
mol,

Answers

Answer:

4) 1.5 mol

Explanation:

Well, the equation is already balanced and the mole to mole ratio of reactants and products are all 1. So if the limiting reactant is HCl and you have 1.5 mol, you do the mole to mole ratio with NaCl and since it is 1 to 1, there'd be 1.5 mol of NaCl.

Rain is-pouring down on you. Your friend asks where so much water
came from. You explain that the water could once have been
a) in a lake.
c) in an ocean.
-b) in-a river.
d) any of the above.

Answers

Answer:

D

Explanation:

It could come from anybody of water around you that had some water evaporated.

The answer is D precipitation comes from all evaporated water

FeCl3
+
NaOH →
Fe(OH)
+
Naci
-
balance plzzzz help I live give u the brainliest

Answers

l don’t think that’s a problem ...

Atoms with the same number of protons but with different electrical charges are called:

Answers

Answer:

It is called ions

Explanation:

(BRAINLIEST QUESTION)
Which answer below best describes what the law of Natural Selection is?

Select one:

a.
Natural selection is the process where those members of a species that can survive environmental hardships reproduce the future offspring with their strong characteristics being passed on, thus evolving the entire species.


b.
Natural selection is the process wherein species evolve over time because those members with common traits tend to survive hardships and produce more offspring.


c.
Natural Selection is the law that states the the natural evolution of a species is dependent on the shifts of the environment.

Answers

The answer is a your welcome

Answer:

I think it's A but I might be wrong

Explanation:

HELP WAAAAAAAAAAAAAAA

Answers

Answer:

5. 0.02 seconds

6. (a) 0.0167 seconds

(b) Period in Lebanon is 0.02 seconds and in the U.S 0.0167 seconds. That means that the U.S. has the faster period.

Explanation:

A little help here please​

Answers

Answer:

Prokaryotic Cells:

- Bacteria

- Unicellular Organisms

- DNA as genetic material

- Ribosomes

- Do not have membrane bound organelles

- Always contain cell wall

Eukaryotic Cells:

- Contains organelles

- Have membrane bound organelles

- Unicellular Organism

- DNA as genetic material

- Ribosomes

- Have loose strand of DNA

- Has nucleus

- Multicellular Organism

- Plant cell

- Animal cell

Explanation:

I have separated them and made the common characteristics in bold. I cannot guarantee that it is correct, these are my educated estimates.

Name one nutrient indicator and explain how it works.

Answers

Answer:

Hi this is Adhira please make me as brainlist

Explanation:

The nutritional status indicators for the CDC Growth Charts include obesity, overweight, underweight, and short stature. Percentiles are used to rank an individual or a group on a growth chart and indicate where either fits in the context of the reference population

What is the formula for the compound?

Answers

Answer:

the correct answer is CO2 (the last one)

I think the answer is CO2, I hope that helps

application of electroplating​

Answers

Answer:

are you interested in tun

Use the pictures below to answer these questions: How does Magnesium become an ion? What is the charge of the Magnesium ion?

Answers

Answer:

Explanation:

The bottom picture shows a Mg atom. There are two electrons on the outside ring. When Mg reacts with something, these 2 electrons are given away. The top picture records that fact.

Zn-71 has a half life of 2.4 minutes. If one had 100g at the beginning, how many grams would be left after 12 minutes?

Answers

3.125g

Explanation

2.4 minutes = 1 half life

so 12 minutes = 5 half lives (12/2.4)

100g/2 = 50g (1 half life)

50g/2 = 25g (2 half lives)

25g/2 = 12.5g (3 half lives)

12.5g/2 = 6.25g (4 half lives)

6.25g/2 = 3.125g (5 half lives)

2. Use the graph below to answer the following questions.
Does this graph represent an endothermic or an exothermic reaction?

How do you know this graph represents that type of reaction?

What is the potential energy of the reactants (PEreactants)?

What is the potential energy of the products (PEproducts)?

What is ΔH of the reaction?
REMEMBER: ΔH = PEproducts - PEreactants

What is the activation energy (Ea) of this reaction?
REMEMBER: Activation Energy = Maximum Energy - PEreactants

Answers

Answer:

The graph represents an endothermic reaction.

The products have more energy than the reactants.

80kJ

160kJ

80kJ

160kJ

The given graph is representing an endothermic reaction as the potential energy reactants are lower than that of the products.

ΔH of the reaction and activation energy is 80 KJ and 160 KJ respectively.

What is the endothermic process?

An endothermic process can be defined as a process with an increase in the enthalpy H of the system. An endothermic process involves an increase in the temperature of the system.

Whether a process occurs spontaneously depends not just on the enthalpy change but also on the entropy change and temperature.

From the graph, the potential energy of the reactants = 80 KJ

The potential energy of the products = 160 KJ

ΔH of the reaction, ΔH = PE(products) - PE(reactants)

ΔH = 160 -80 = 80 KJ

The activation energy (Ea) of this reaction will be:

Activation Energy (Ea) = Maximum Energy - PE(reactants)

Activation Energy = 240 - 80 = 160 KJ

Learn more about the endothermic process, here:

brainly.com/question/13818956

#SPJ2

Other Questions
Amy is solving the equation using the steps shown.Which could be the correct next step in solving the equation?Subtract 2 from both sides of the equation to yield (x 2 16) = 0.Subtract 2 from both sides of the equation to yield (, x , 2, 16) = 0.Multiply (x 2 16)(x + 2) on the left side of the equation to yield x 3 + 2x 2 16x 32 = 0.Multiply (, x , 2, 16)(, x, + 2) on the left side of the equation to yield , x, , 3, + 2, x, , 2, 16, x, 32 = 0.Factor (x 2 16) on the left side of the equation to yield (x + 4)(x 4)(x + 2) = 0.Factor (, x , 2, 16) on the left side of the equation to yield (, x, + 4)(, x, 4)(, x, + 2) = 0.Add 16 to both sides of the equation to yield x 2(x + 2) = 0.Add 16 to both sides of the equation to yield , x , 2, (, x, + 2) = 0. A flower bed is in the shape of a triangle with one side twice the length of the shortest side, and the third side is 19 feet more than the length of the shortest side. Find the dimensions if the perimeter is 167 feet.PLS HELP URGENTT Mary wanted to know if seeds needed water to start growing or if any kind of liquid would work. Mary set up several experiments to find out. She used radish seeds, paper towels, plastic bags, and different kinds of liquid in her experiment. Mary put three seeds into each bag. She then used 30mL of liquid to wet a paper towel and put a different paper towel in each bag. Mary put all of the bags on the same table next to a window so that they could each get the same amount of light. She waited three days and then checked her plants.independent variable:dependent variable:control:experimental group:control group: Put the following equation of a line into slope-intercept form, simplifying allfractions.2y - 2 = -14 Write an Equation for each of the lines on the graph. Which value of y makes the equation y+4.2=21 true? simplify the expression (9n+ 4)-(-1/2n-7) Convert -439 to radians Mrs. Chavis's statistics class has 26 students in it, 14 girls and 12 boys. She uses a calculator to select two students at random to solve a problem on the board. what role did minorities and women play in filling the gap in jobs on the home front during wartime evaluate the expression 5 /6 + -3 /5 A bakery sells glazed donuts for $1.09 each. Cinnamon bagels and onion bagels are $1.59 each. Max buys x donuts, y cinnamon bagels, and z onion bagels. Which expression represents the total amount Max spent at the bakery?A. 1.09x + 1.59yzB. 1.09x + 1.59y + 1.59zC. 1.09x + 3.18(y + z)D. (1.09 + 1.59)(x + y + z) what is the first step in creating the federal budget? Why is the tensile strength of a material important to consider when building a structure? Answer in a one page essay!!! Subtract using a vertical format. (5x3 + 5x + 2) (5x2 + 2x + 1) What is the height of a triangle with an area of 67. 5 square meters and a base of 9 meters?. 3. Formuleaz dou argumente care s susin afirmaia:Fiecare copil trebuie s aib o identitate. The very act of you observing somethingwill disturb the system is known as: Can someone help me with this, and if you can Explain it. HURRY PLEASEWhich timeline best shows the history of the development of cell theory?