1. Which of these is NOT found in the nucleus of an atom?
neutrons
protons
electrons
the mass of the atom

Answer:

C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.

Explanation:

From the analogy of the problem presented, we can see that Henry is grossly incorrect. His conclusion from the process of the experiment he carried out is completely wrong.

Physical changes are changes that alters the physical properties of matter particularly the form and state.

Chemical changes leads to the formation of a new kind of matter.

 We can see that since the salt was obtained back after evaporation, no change has occurred to it.

Therefore, evaporation in itself is a physical change process.

Answer:

c on ed

Explanation:

Answer:

Titanium is another metal that's commonly used in aerospace engineering. It's strong, lightweight, Aluminum isn't the strongest metal, but it maintains a perfect balance of strength and low weight that make airplanes fly

Explanation:

vote mee as the brainliest

Answer:

it weight were so thin

explanation

With a weight roughly a third lighter than steel, it allows an aircraft to either carry more weight, or become more fuel efficient. High Strength — Aluminum's strength allows it to replace heavier metals without the loss of strength associated with other metals, while benefitting from its lighter weight

Answer:

Acid

Explanation:

;)

Answer:

D if I’m correct

Explanation:

Answer:

community

Explanation:

Answer:

The correct answer is population. I took the test and got it right.

Answer:

Your average speed was 3.77 Miles per hour

Explanation:

Answer: is a base

Explanation:

Answer:

two moles

There are two moles.

Explanation:

Answer:

42.07%

Explanation:

Molar mass of Na3PO4 = 23×3 + 31 +16×4

= 69+ 31+64= 164 g/mol

Mass of Na in this compound is 69

Percentage of sodium in sodium phosphate = 69/ 164×100

Percentage of Na = 42.07%

Answer:

T2 =21.52°C

Explanation:

Given data:

Specific heat capacity of sample = 1.1 J/g.°C

Mass of sample = 385 g

Initial temperature = 19.5°C

Heat absorbed = 885 J

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = Final temperature - initial temperature

885J = 385 g× 1.1 J/g.°C×(T2 - 19.5°C )

885 J = 423.5 J/°C× (T2 - 19.5°C )

885 J / 423.5 J/°C = (T2 - 19.5°C )

2.02°C = (T2 - 19.5°C )

T2 = 2.02°C + 19.5°C

T2 =21.52°C

Answer:

7.5 moles of hydrogen is required

Explanation:

Given data:

Number of moles of H₂ needed = ?

Number of moles of NH₃ = 5 mol

Solution:

Chemical equation:

N₂ + 3H₂     →     2NH₃

Now we will compare the moles of ammonia and hydrogen.

         NH₃       :         H₂  

          2           :          3

          5           :         3/2×5 = 7.5 mol

Thus, 7.5 moles of hydrogen is required.

Extensive properties, such as mass and volume, depend on the amount of matter that is being measured. ... Both extensive and intensive properties are physical properties, which means they can be measured without changing the substance's chemical identity

Answer:

1)They have different densities.

2) The molecules are packed differently

Explanation:

Oil and Water have different densities The first reason that water and oil don’t mix is because their molecules are packed differently. The molecules of water are packed very densely. (Would be good to show water molecules packed densely) In one glass of water, there are more molecules than the number of known stars in the universe!

Answer:

diff densities

Explanation:

Answer: An atom with 6 protons, 5 electrons, and 7 neutrons

Explanation: In this case, neutrons do not matter as they have a charge of 0, or no charge. A proton has a charge of +1 and an electron has a charge of -1. Since there are 6 protons, the total charge of the protons would be +6. Since there are 5 electrons the total charge of the electrons would be -5. +6 - 5 would result in a charge of +1. This means that this atom would have an overall charge of + 1. Basically, if there is one more proton than electron, then the overall charge of the atom will be +1 but if there is one more electron than proton, then the overall charge of the atom will be -1.

Answer:

[tex] \frac{1839}{18} = 102.16[/tex]

Take 102.16 and multiply by avogadros #

and you get 6.33 × 10^25 otherwise A

Answer:

Answer is A

Explanation:

I just took this.

The molality of a solution : m = 0.33 mol/kg

Given

2 moles of NaOH in 6 kg  of water

Required

The molality

Solution

Molality shows how many moles are dissolved in every 1000 grams of solvent.

m = n x (1000/p)

m = Molality

n = number of moles of solute

p = solvent mass (grams)

Input the value :

solute : NaOH

solvent : water

m = 2 moles : 6 kg

m = 0.33 mol/kg

Answer:

HOLY WOAH

Explanation:

YES

Answer:

Explanation:

Solution required is .15 M 500 mL sodium fluoride .

molecular weight of sodium fluoride = 42

one mole of sodium fluoride = 42 grams

No of moles contained in the solution of .15M , 500 mL solution

= .15 x 0.5 moles = .075 moles

1 mole = 42 g

.075 moles = .075 x 42 = 3.15 grams .

So mass of sodium fluoride required = 3.15 g .

Answer:

A, 4,3,3,4

B, 3,2,2,3

C, 2,6,2,3

D, 1,2,1, 1

Answer:

We could make the surface tension to decrease by removing and causing a disruption to the intermolecular forces(hydrogen bonds).

Explanation:

To explain this answer, we will consider an experiment whereby a paper clip is made to rest at the top surface of water inside a container/beaker.

First of all, the intermolecular forces present in water are also known as hydrogen bonds.

It's relationship with surface tension is that when there is high surface tension in the water, this high tension will allow the paper clip to rest on top of the hydrogen bonds present at the top surface in between the water molecules.

However, the surface tension will decrease when we remove or cause a disruption to the intermolecular forces (hydrogen bonds).

don't know sorry.........

Answer:

European stability mechanism

Answer:

False

Explanation:

Heres what its made of:

The core is made of hot, dense plasma (ions and electrons), at a pressure estimated at 265 billion bar (3.84 trillion psi or 26.5 petapascals (PPa)) at the center. Due to fusion, the composition of the solar plasma drops from 68–70% hydrogen by mass at the outer core, to 34% hydrogen at the core/Sun center.

Answer:

Not enough sunlight is captured in these areas of the leaves.

Explanation:

Photosynthesis is the process whereby green plants manufacture their food using carbon dioxide and water in the presence of sunlight.

The sunlight is the energy source which drives this chemical change or reaction.

Answer:

Over time, the limestone is broken down into its chemical parts and may come back to the surface as volcanic CO2 (in the atmosphere). From the atmosphere, the CO2 might again become part of the biosphere by molluscs or corals absorbing the CO2 to help make their shells

Explanation:

Over a long period of time, we would take a look at the rock "limestone" through the rock cycle. Limestone being a sedimentary rock would be converted to marble, a metamorphic rock if subjected to metamorphic conditions over an extensive period of time.