I need help!!!! please

Answer:

B

Explanation:

Isotopes have the same number of protons but different number of neutrons.

The true statement is,

So, option C is correct one.

The isotopes have different physical properties like freezing point , mass, melting or boiling point etc because they have different mass number .

learn about isotopes,

https://brainly.com/question/11904263

#SPJ2

Answer:

Answer:

6.05 g

Explanation:

Use the density to convert the volume to a weight.

(5.00 mL) × (1.21 g/mL) = 6.05 g liquid plant food

You will need 6.05 g liquid plant food.

Answer:

3.34 M or 3.34 mol/L

Explanation:

The formula for molarity is moles of solution ÷ liters of solution. So, we have to convert grams into moles and mL to L.

To convert grams to moles, first find the molar mass of CH₃COOH by looking at the atomic mass of each individual element.

C - 2(12.01) = 24.02

H - 4(1.01) = 4.04

O - 2(16.00) = 32.00

= 60.06

Now divide the number of grams by the molar mass.

10.0 g CH₃COOH ÷ 60.06 g = 0.167 mol CH₃COOH

To convert milliliters to liters, divide by 1000.

50.0 mL ÷ 1000 = 0.05 L

Now we can calculate the molarity.

M = moles of solution ÷ liters of solution

= 0.167 mol ÷ 0.05 L

= 3.34 M or 3.34 mol/L

The molarity is 3.34 M.

Hope that helps.

Answer: 89.57 %

Hope it helps

Answer:

pcl3 is the empirical formula of the compound

Answer:

0.8833 mole of C3H8

Explanation:

Given:

Mass of C₃H₈ (Propane) = 38.95 gram

Computation:

Molar mass of C = 12.01

Molar mass of H = 1.008

Molar mass of C₃H₈ (Propane) = 3(12.01) + 8(1.008)

Molar mass of C₃H₈ (Propane) = 36.03 + 8.064

Molar mass of C₃H₈ (Propane) = 44.094

Number of mol in 38.95 gram Propane = Mass / Molar mass

Number of mol in 38.95 gram Propane = 38.95 / 44.094

Number of mol in 38.95 gram Propane = 0.88334

Answer:

Use the Periodic Table to find molar masses.

Propane (C3H8), a common fuel, reacts with oxygen to form carbon dioxide and water according to the equation below:

C3H8 + 5O2 → 3CO2 + 4H2O

If a propane heater burns 38.95 g C3H8, it consumes

38.95 mol C3H8.

0.8830 mol C3H8.

1 mol C3H8.

44.10 mol C3H8.

Part 2

How many moles of oxygen are required to produce 37.15 g CO2?

37.15 g CO2 = 1.407 mol O2

Part 3

What mass of propane is necessary to react with the amount of oxygen calculated in the previous question?

12.41   g C3H8    

Answer:

4.30 × 10²⁰ atoms

Explanation:

You need to find out how many moles you have.  First, convert milligrams to grams.

62.5 mg × (1 g)/(1000 mg) = 0.0625 g

Next, use the molar mass to convert from grams to moles.

0.0625 g ÷ 87.62 g/mol = 7.13 × 10⁻⁴ mol

To convert from moles to atoms, you need to use Avogadro's number (6.022 × 10²³).  Avogadro's number is the number of atoms in a mole.

7.13 × 10⁻⁴ mol × 6.022 × 10²³ atoms/mol = 4.296 × 10²⁰ ≈ 4.30 × 10²⁰ atoms

You will have 4.30 × 10²⁰ atoms of strontium.

The number of Strontium atoms are 4.30 × 10²⁰ atoms

Given:

Mass of Strontium = 62.5 mg × (1 g)/(1000 mg) = 0.0625 g

Molar mass of Strontium = 87.62 g/mol

To find:

Moles of Strontium = ?

It is defined as given mass over molar mass.

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\\\\\text{Number of moles}=\frac{0.0625 g}{87.62 g/mol }\\\\\text{Number of moles}=7.13 * 10^{-4} mol[/tex]

Avogadro's number is the number of atoms in a mole (6.022 * 10²³)

Conversion of moles into atoms:

[tex]7.13 × 10^{-4} mol * 6.022 * 10^{23} atoms/mol \\\\\text{ Sr atoms}= 4.296 * 10^{20} = 4.30 * 10^{20} atoms[/tex]

Thus, Strontium atoms will be 4.30 × 10²⁰ atoms.

Find more information about Number of moles here:

brainly.com/question/15356425

Answer:

Ingredients OR tenderising

Explanation:

Answer:

Explanation:

Given:

Amount in calories = 450 calories

Amount in joules = 3.5 × 100 joules

Find:

Computation:

We know that,

1 calories = 4.184 joules

So,

Amount in calories = 450 calories

= 450 × 4.184

= 1,882.8 joules

Amount in joules = 3.5 × 100 joules

=  [3.5 × 100] / 4.184

= 83.652 calories

Answer:

The SI system : The international system of units.

It is a scientific method of expressing the magnitudes or quantities of important natural phenomena.

Benefits of SI system

Answer:

[tex]\Large \boxed{\mathrm{A}}[/tex]

Explanation:

Rust formed from iron and oxygen combining is a chemical change, because in a chemical change, the resulting substance(s) will have different properties from the substance(s) before the chemical change.

I cant comment... So is it Right?

THIS IS THE COMPLETE QUESTION BELOW

46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the four substances whose properties are given, which is the most likely identity of this substance?

Substance Density (g/cm3) Melting Point (°C) Boiling Point (°C)

molybdenum 10.28 2,623 4,639

mercury 13.53 -39 357

hafnium 13.31 2,233 4,603

lead 11.34 327 1,749

A.

molybdenum

B.

mercury

C.

hafnium

D.

lead

Answer :

The correct option is OPTION C.

(C) Hafnium

Explanation;:

We were given the mass of substance as (m) = 46.9 g

The Volume of substance as (V) = 3.5 Cm^3

But we know Density of substance.= Mass/it's Volume

Then Density=46.9/3.5

=13.4g/Cm^3

From the questionthe given substance is solid at room temperature, and let us take Mercury as an example , Mercury is liquid at room temperature. ThenMercury cannot be the answer.

Base on the determined density which is 13.4 and the density of Hafnium also is 13.31 g/cm3 and it is solid at room temperature. Therefore, Hafnium is the only likely element here.

Answer:

See explanation

Explanation:

Cu- 28.4/63.5, Br- 71.6/80

Cu- 0.447/0.447, Br- 0.895/0.447

Cu- 1, Br - 2

Empirical formula = CuBr2

b)

K- 39.0/39, C-12.0/12, H- 1.01/1, O- 47.9/16

K= 1, C-1, H- 1. O-3

Empirical formula= KHCO3

c)

Ag- 77.3/108, P-7.4/31, O-15.3/16

Ag-0.716/0.239, P- 0.239/0.239, O-0.956/0.239

Ag-3, P-1, O-4

Empirical formula= Ag3PO4

d)

H-0.57/1, I- 72.1/127, O-27.3/16

H- 0.57/0.57, I- 0.57/0.57, O-1.71/0.57

H-1, I-1, O- 3

Empirical formula= HIO3

Answer:

hexagonal layers slide

Explanation:

The layers in graphite can slide over each other because the forces between them are weak. The delocalised electrons are free to move through the structure, so graphite can conduct electricity.This makes graphite slippery, so it is useful as a lubricant .

i think it's right

hope it helps :)

Answer: Johannes Kepler

Answer:

i believe the answer us kepler

Explanation:

Answer:

in the fermentati0n process glucose [C6H12O6]c of food is converted into ethanol [ethyl alchol, C2H5OH] and Co2 by yeast cell .In this process yeast cell produce in vertase and zymase enzyme which convert glucose into alcohol .

i.e. c6H12O6========> C2H5OH+Co2+energy

Answer:

"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."

Explanation:

When enthalpy is positive and delta H is greater than zero, this means that a system absorbed heat. This is called an endothermic reaction. When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction.

The sign of q for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings are gaining heat from the system, the temperature of the surroundings increases.

Learn more about the endothermic reaction here: brainly.com/question/6506846

#SPJ2

Complete Question:

In ∆ABC, if sin A = 4/5 and tan A = 4/3, then what is cos A?

Answer:

[tex]cos A= \frac{3}{5}[/tex]

Explanation:

Given

[tex]sin A = 4/5[/tex]

[tex]tan A = 4/3[/tex]

Required

[tex]cos A[/tex]

In trigonometry;

[tex]tanA = \frac{sinA}{cosA}[/tex]

Multiply both sides by cosA

[tex]cos A * tanA = \frac{sinA}{cosA} * cos A[/tex]

[tex]cos A * tanA = sinA[/tex]

Divide both sides by tanA

[tex]\frac{cos A * tanA}{tanA} = \frac{sinA}{tanA}[/tex]

[tex]cos A= \frac{sinA}{tanA}[/tex]

Substitute values for sinA and tanA

[tex]cos A= \frac{4/5}{4/3}[/tex]

[tex]cos A= \frac{4}{5} / \frac{4}{3}[/tex]

[tex]cos A= \frac{4}{5} * \frac{3}{4}[/tex]

[tex]cos A= \frac{4 * 3}{5 * 4}[/tex]

[tex]cos A= \frac{3}{5}[/tex]

Answer:

C. Experiments test the scientists' ideas.

Explanation:

Experiments test the scientists' ideas. Therefore, the correct option is C.

By testing ideas and hypotheses, experiments are an essential part of the scientific method and aid scientists' understanding of the world. Science uses regulated procedures to detect particular phenomena, track results, and collect data. These studies give researchers a chance to investigate cause-and-effect relationships, detect patterns, and draw conclusions based on the data. Scientists can test their ideas, theories, and predictions by systematically adjusting various factors to see whether experimental results confirm or disprove them.

Therefore, the correct option is C.

Learn more about Experiments, here:

https://brainly.com/question/15088897

#SPJ2

Answer:

the concentration in moles per litre of is

Explanation:

Molarity

mark me as a a brainlist answer

Answer:

Explanation:

given

volume=1.85 d m^3

T=27 degree C=27+273 k=300 k

P=750 mmHg

mass of zinc=?

we know that PV=nRT

n=m/M

PV=mRT/M

M for zinc=65.4

PVM=mRT

m=PVM/RT

m=750*1.85*65.4/0.0821*300

m=90742.5/24.63

m=3684

hope this will help u

Explanation:

Hi there!!

you asked to multiply these all right,

you can simply multiply it ,

=3cm × 4 cm × 1cm

= 12cm^2×1cm (4×3=12)

= 12cm^3 (12×1=12)

Therefore, theanswer is 12 cm^3.

Hope it helps..

Answer:

The option closest to the percentage yield is option;

d. 81.1

Explanation:

The given chemical equation of the reaction is presented as follows;

CaO (s) + H₂O (l) → Ca(OH)₂

The mass of CaO in the experiment, m = 2.00 g

The volume of water with which the CaO was reacted = Excess volume of water

Number of moles = Mass/(Molar mass)

The mass of Ca(OH)₂ recovered, actual yield = 2.14 g

The molar mass of CaO = 56.0774 g/mol

The number of moles of CaO in the reaction, n₁ = 2.00 g/(56.0774 g/mol ≈ 0.036 moles

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

The number of moles of Ca(OH)₂ in the reaction, n₂ = 2.14 g/(74.093 g/mol) ≈ 0.029 moles

From the given chemical reaction, one mole of CaO reacts with one mole of H₂O to produce one mole of Ca(OH)₂

Therefore, 0.036 moles of CaO will produce 0.036 moles of Ca(OH)₂

Mass = Number of moles × Molar mass

The mass of 0.036 moles of Ca(OH)₂ ≈ 0.036 moles × 74.093 g/mol = 2.667348 grams

∴ The theoretical yield of Ca(OH)₂ = 2.667348 grams

[tex]Percentage \ yield = \dfrac{Actual \ yield}{Theoretical \ yield} \times 100 \%[/tex]

The percentage yield = (2.14 g)/(2.667348 grams) × 100 = 80.23%

Therefore, the option which is closest is option d. 81.1.

Answer:

CNa203

Explanation:

thats is method in the picture send

Explanation:

Answer:

1.29* 10^2

Explanation:

multiply them and then round

Answer:

Ver las respuestas abajo.

Explanation:

Este problema se puede resolver conociendo la relacion entre horas y minutos, sabemos que:

1 hora [h] → 60 minutos [min]

De esta manera:

2 [min] = 2/60 = 0.033 [h]

15 [min] = 15/60 = 0.25 [h]

30 [min] = 30/60 = 0.5 [h]

10 [min] = 10/60 = 0.166 [h]

6 [min] = 6/60 = 0.1 [h]

20 [min] = 20/60 = 0.33 [h]

5 [min] = 5/60 = 0.0833 [h]

Answer:

These are compounds.

Explanation:

As it is formed by chemically bonding of two elements C ( carbon) and H (hydrogen) .

Answer:

Butane and benzene are both compounds. They contain multiple elements bonded together in a specific ratio. Kerosene and gasoline are mixtures because they are combinations of several compounds. Oxygen is an element because it is made up of only one type of atom.

Explanation: