True/False: There are about 400 known elements

Answers

Answer 1

Answer: false

Explanation:

there are no more then 112 known elements.

Answer 2

Answer:

false

Explanation:

their are only 118 element


Related Questions

True or False- Waves are caused by the water being pushed by the wind, which transfers energy, that can cause erosion to the shorelines .

Answers

Answer:

false

Explanation:

Waves are created because othe the lunar pull with out the moon we wouldnt have waves

Tectonic Plates
Tectonic Plates
Which of the following is an accurate description of the movement of the tectonic plates in the diagram?
O A. Plate A is sliding past plate B.
O B. Plate A and plate B are diverging.
OC. Plate A and plate B are of equal density and are colliding.
OD. Plate A is denser than plate B, which results in subduction.

Answers

D. Plate A is denser than plate B, which results in subduction.

PLEASEEE HELP ASAPPPPP

Answers

Answer: answer A

Explanation: because it gives more detail and a summarizations

A 170.0 g sample of an unidentified compound contains 29.84 g sodium, 67.49
g chromium, and 72.67 g oxygen. What is the compound's empirical formula?

Answers

The empirical formula : Na₂Cr₂O₇

Further explanation

Given

170 g sample contains :

29.84 g sodium, 67.49  g chromium, and 72.67 g oxygen

Required

The compound's empirical formula

Solution

mol ratio of elements :

Na : 29.84 : 23 g/mol = 1.297

Cr : 67.49 : 51,9961 g/mol = 1.297

O : 72.67 : 16 g/mol = 4.54

Divide by 1.297

Na : Cr : O = 1 : 1 : 3.5 = 2 : 2 : 7

How many moles are in 6.777 x 1023 atoms of CO2. Watch your significant figures. Question 2 options: 1 atoms CO2 1.125 moles CO2 1.13 moles 1.13 atoms CO2

Answers

Answer:

1.13moles

Explanation:

Given parameters:

Number of atoms  = 6.777 x 10²³ atoms

Unknown:

Number of moles  = ?

Solution:

A mole of a substance contains the avogadro's number of particles

       6.02  x  10²³ particles   = 1 mole

      6.777 x 10²³ atoms will contain [tex]\frac{ 6.777 x 10^{23} }{6.02 x 10^{23} }[/tex]   = 1.13moles

please help me with this question/

Answers

ur answer is A

hshsbdndnensj

Answer:

4 of each protons and electrons

Explanation:

since the atomic number is 4 it would contain both the same number of protons and electrons

The sum of the atomic masses for any compound is the compound’s:
Empirical mass
Compound mass
Atomic mass
Molar mass

Answers

The correct answer is molar mass

Why did early people most likely choose to settle in Mesopotamia?

Answers

Answer:

People wanted to settle there because it had good living conditions. There was rich soil, and lots of water sources.

I hope this helps!

Which of the following requires more energy then they produce?
Exothermic
Endothermic
(the subject is science but it wasn’t an option)

Answers

Answer:

The answer is endothermic

4. How many moles of H, would be
produced from 47 grams of H2SO4?
2A1 +3H,504 → Al2(SO4)3 +3H2

Answers

Answer:

0.48 moles of H₂ are produced.

Explanation:

Given data:

Number of moles of H₂ produced = ?

Mass of H₂SO₄ = 47 g

Solution:

Chemical equation:

2Al + 3H₂SO₄    →    Al₂(SO₄)₃ + 3H₂

Number of moles of H₂SO₄ :

Number of moles = mass/molar mass

Number of moles = 47 g/ 98 g/mol

Number of moles = 0.48 mol

Now we will compare the moles of H₂SO₄ and  H₂

                       H₂SO₄      :        H₂

                           3           :          3

                         0.48       :        0.48

Thus, 0.48 moles of H₂ are produced.

Precipitation falls in these two forms: Solid / Liquid / Gas I’ll give you 77 and read the pdf

Answers

Answer:

It falls in Liquid and Solid.

Explanation:

What is the atomic mass of this atom?

Answers

Answer:

3

Explanation:

The atomic mass is equal to the number of protons in an atom (and electrons if the atom is neutral).

what is the change in freezing point of a 1.75 molal solution of nacl in water? the kf for water is 1.86 degrees c/m.

Answers

Answer:

-6.51

Explanation:

Multiply 1.86 x 2 x 1.74 and then you get your answer.

Answer:

As the molality increases by 1 m, there is a corresponding decrease of 1.86°C in the solution’s freezing point.

Explanation:

Anser on EDge

Write the complementary RNA strand for the following DNA strand. TAC ACC TTG ACG

Answers

ATG TGG AAC TGCPlease let me know if I am wrong.

Answer:

ATG TGG AAC TGC

Explanation:

ATG TGG AAC TGC

Which are not combination reactions?
Check all that apply.
A. 2H2O + 2H2 + O2
B. H2 + Cl2 → 2HCI
C. Fe + MgO + Mg + FeO
D. 2Na + Cl2 → 2NaCl

Answers

Answer:

A and c

Explanation:

In A the product is added to the reactant, so the real reaction is (2H2O = 2H2+O2).

In B hydrogen and clorine are combined to give hydrochloric acid and 2 is used to balance the reaction in the product, so it's a combination reaction .

In C the case is similar to A , so the real reaction is (Fe+MgO = Mg + FeO ) this is displacement reaction where a more reactive element takes place of a less reactive element .

In D sodium reacting with Chlorine to give sodium chloride ,so we conclude that it's a combination reaction .

whoever answers first will get brainliest! this is times so pls help!

You are titrating a 125 mL sample of KOH solution; the pH meter reads 7.00 after the addition of 84.7 mL of 0.750 M HNO3.

What is the concentration of the KOH solution?

A. 0.125 M KOH
B.0.750 M KOH
C.0.508 M KOH
D. 0.0635 M KOH

thanks so much!

Answers

I’m pretty sure it would be D

A compound has a molar mass of 100 g/mol and the percent composition (by mass) of 65.45% C, 5.45% H, and 29.09% 0. Determine the empirical formula and the molecular formula.

A) CHO and C6H6O6

B) C3H3O and C6H6O2

C) C3HO and C6H2O2

D) CH2O and C4H8O4

E) CH4O and C3H12O3

Answers

Answer:

B) C3H3O and C6H6O2

Explanation:

Given data:

Molar mass of compound = 100 g/mol

Percentage of hydrogen = 5.45%

Percentage of carbon = 65.45%

Percentage of oxygen = 29.09%

Empirical formula = ?

Molecular formula = ?

Solution:

Number of gram atoms of H = 5.45 / 1.01 = 5.4

Number of gram atoms of O = 29.09/ 16 = 1.8

Number of gram atoms of C = 65.45 / 12 = 5.5

Atomic ratio:

            C                      :      H            :         O

           5.5/1.8              :     5.4/1.8     :        1.8/1.8

            3                      :        3          :        1

C : H : O = 3 : 3 : 1

Empirical formula is C₃H₃O.

Molecular formula:

Molecular formula = n (empirical formula)

n = molar mass of compound / empirical formula mass

Empirical formula mass = 12×3 + 1.01 ×3 + 16×1 = 55.03  

n = 100 / 5503

n = 2

Molecular formula = n (empirical formula)

Molecular formula = 2 (C₃H₃O)

Molecular formula = C₆H₆O₂

Please answer this question please brianlest

Answers

made of cells, uses stimuli and it adapts
Order, sensitivity, response to environment, reproduction, growth, development, regulation, homeostasis, and energy . Hope this helps

what does 'potable water' mean?

Answers

Answer:

Potable water, also known as drinking water, comes from surface and ground sources and is treated to levels that that meet state and federal standards for consumption.

Scott and his classmates were looking at an animal cell under a microscope. They are trying to locate the cell's DNA, which is found in its chromosomes. Where should Scott look to find the chromosomes?

In the mitochondria

In the cell nucleus

In the cytoplasm

In the cell vacuole

Answers

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells.

True/False: Atoms of the same elements have different properties

Answers

Answer: True

Explanation:

If the temperature of a gas in a balloon remains constant but the pressure
is decreased, the volume of the balloon will
decrease
increase
remain the same
not enough information to predict

Answers

Answer:

increase

Explanation:

if the pressure goes down then the gas will spread out more, meaning the volume will increase

How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions?
1. They used X-ray analysis.
2. They used litmus testing.
3. They burned the paint to examine what elements were left after the chromium was burned off.
4. They studied the density of modern yellow paint to that of 100-year-old paint.

Answers

Answer:

I think the answer is A - they used X-ray analysis.

Explanation:

Answer:They used X-ray analysis

Explanation:

It’s in the text

If she traveled 10 m in 5 seconds, what was her average speed?

Answers

average speed = distance traveled divided by time taken. so 10 divided by 5, which is 2. her average speed was 2m per second. hope this helps!

Balance the equation
AgBr +
GaPO4 →
Ag3PO4 +
GaBi3

Answers

Answer:

3AgBr + GaPO4 ----> Ag3PO4 + GaBr3

Explanation:

The answers plzzzzzzz

Answers

Answer:

ok, whats the question

Explanation:

What is the Sl unit for energy? Be sure to give the full name for the unit

Answers

Answer:

Joules

Explanation:

is mass conserved in 2Na+2H2O=2NaOH+H2​

Answers

Answer:

yes mass conservation is in 2Na+2H2O=2NaOH+H2​

Explanation:

it tells how many atoms or molecules of a reactant or a product take part in the reaction


Convert a measurement of 89 cg to its equivalent in mg

Answers

Answer:

1 cg = 10 mg

Explanation:

So, 89cg = 89 * 10 = 890mg!

Pls thank, 5star, and brainliest!

By February of 1861, how many states seceded from the Union?
5
11
9
7

Answers

11 states seceded the from the union in 1861

Answer:

D. 7

Explanation:

i did it

Other Questions
Why does the sum of the two given angles equal 180? (2x+1)+(x-7)=180 BRAINLIEST AND 30 POINTS PLEASE HELP!. Explain in two paragraphs , the characteristics of the manor system during the Middle Ages. And explain why people lived in this feudal society . help me out pleaseeee Consider one-dimensional heat conduction through a large plane wall with no heat generation that is perfectly insulated on one side and is subjected to convection and radiation on the other side. It is claimed that under steady conditions, the temperature in a plane wall must be uniform (the same everywhere). Is this claim reasonable Which features do sound waves have that ocean and light waves do not? Check all that apply.compressionrarefactionamplitudewavelengthcrestsfrequencyspeed is high seismic activity belong in the divergent, convergent, or in both? Suppose you know that S and Y are complementary, and that mS = 2(mY) 60. Find mY.The value of mY is I NEED HELP!!! PLS Compare and contrast animal welfare and animal rights.3-5 sentences How many moles of NaCl are in 2.35 liters of a 4.67 M solution? PLEASE HELP DUE TOMORROW!what are the advantages of harvesting more crops and trees to reducing carbon emissions?And what are disadvantages of harvesting tree and crops for reducing carbon emissions? To rent a Jet Ski at Sam's it cost $25 plus $3 per hour. Write an equation that represents Sam's charges. Wanted to help out those that needed points but anywaywhats ya sexuality and spill the tea This drawing illustrates a person's Sixth Amendment right to a A: fair trial B: jury trial C: speedy trial cual es la respuesta correcta? un rombo se diferencia de un cuadrado en.... 1- que puede tener sus lados iguales 2a2 2-que puede tener sus angulos iguales 2a2 3-ambas respuestas anteriores son correctas porfavor, necesito que me ayuden, es para ahora The opium wars were a series of 19th Century conflicts fought mainly between a) india and japan b) china and japan c) Great britain and china D) great britian and india which one ? In The Dragonfly, how does the poet develop the theme of life is temporary?She first describes the dragonfly as ceaseless movement and then describes it as a fallen husk.She first describes the dragonfly as doubled winged and then describes it as twice-born and split.She first describes the dragonfly as a dart and then describes it as a rocket. She first describes the dragonfly as made of nothing and then describes it as a link between water and air. The cost of admission to a popular music concert for 4 children and an adult was$54. The admission for 8 children and 3 adults in another music concert was $122.How much was the admission for each child and adult? Rank the four fundamental forces from strongest to weakest. Use 1 to indicate the strongest force and 4 to indicate the weakest force. The gravitational force: The electromagnetic force: The strong nuclear force: The weak nuclear force: HELP!!!!! It's REALLY easy, but you can't retake this practice assignment, so help