i need help with chem ????????

Explanation:

The increase in mass is because the iron fillings have combined with a sulfide to produce iron sulfide and so the mass will increase.

In such a reaction like this, the mass of the reactants must be conserved. By so doing, the mass of reactants and products must be the same.

When two substances combine together, their masses added up to that of the individual masses. This helps to conserve the mass.

Answer:

Covalent

Explanation:

Ionic gives or takes electrons

Metallic isn't really a "type" of bond

Answer:

Because nitric acid is acidic in nature and sodium hydroxide is basic in nature so when acid and base react they become neutral.

We have that for the Question,it can be said that How much hydrogen chloride was used in the reaction is

From the question we are told

Magnesium (24.30g) reacts with hydrogen chloride (xg) to produce hydrogen gas(2.04g) and magnesium chloride (96.90g).

Generally the equation for the Reaction is  is mathematically given as

Mg+2HCl-----MgCl2+H2

Grams of MgCl2=[tex]\frac{96.9*24.30}{2.04}\\[/tex]
Grams of MgCl2=1154.25g

Therefore

ON cK -12

How much hydrogen chloride was used in the reaction is

x=74.42

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Answer:

false

Explanation:

Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering.

Answer:

The correct option is;

c. Bromine, zinc, calcium, radium

Explanation:

The atomic radii of the elements as arranged in the periodic table decreases across the period and increases down the groups

The location of each of the elements are;

Zinc: Period 4, Group 12

Calcium: Period 4, Group 2

Radium: Period 7, Group 2

Bromine: Period 4, Group 17

Therefore, the element with the largest atomic radius = Radium

The element with the smallest atomic radius = Bromine

Calcium comes before zinc on period 4, therefore, the atomic radius of calcium is larger than that of zinc

The rank of the elements from smallest to largest atomic radius is therefore;

Bromine, zinc, calcium, radium.

Answer:

ok

Explanation: whatever you think

Answer:

In Niels Bohr's theory of the atom, electrons absorb and emit radiation of fixed wavelengths when jumping between fixed orbits around a nucleus. The theory provided a good description of the spectrum created by the hydrogen atom, but needed to be developed to suit more complicated atoms and molecules.

Explanation:

Answer:

Here

Explanation:

Some assume our planet's changing distance from the sun causes the change in the seasons. That's logical, but not the case for Earth. Instead, Earth has seasons because our planet's axis of rotation is tilted at an angle of 23.5 degrees relative to our orbital plane, that is, the plane of Earth's orbit around the sun

Josh is washing glasses with soap and water. He is afraid to carry the glasses because they are slippery. Josh could dry them with a towel to keep the glasses from being slippery.

Glasses are visual eyewear that have lenses fixed in a frame that holds them in front of a person's eyes. The frame often has a bridge over the nose and arms that rest over the ears. Glasses are also known as eyeglasses or spectacles.

The term "glasses" likely originated from the word "spyglass," which was originally used to describe "a pair of eyeglasses" that had to be held up to the eyes in order to be fully effective.

Eyeglasses, often known as glasses or spectacles, are lenses that are mounted in frames and worn in front of the eyes to improve vision or to correct astigmatism, myopia, or hyperopia.

Thus,  Josh could dry them with a towel to keep the glasses from being slippery.

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The bouncing back of light waves observed when light waves hit ice and most of them bounce off and radiate back into space is called reflection.

Light waves are a form of waves which produces visible sensitization of the eyes

Light waves have properties of waves such as:

When light waves hit ice, most of them bounce off and radiate back into space.

This property of light waves is known as reflection.

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When light waves hit ice, most of them bounce off and radiate back into space, hence, ice is best described as a reflective surface.

A reflective surface is one which can cause incident light to bounce back (reflection).

According to this question, when light waves hit ice, most of them bounce off and radiate back into space. This means that most of the incident light reflects off the ice surface.

Therefore, the ice surface is best described as a reflective surface.

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Answer:

No question so I'm just taking the points

Answer:

A & D

Explanation:

all of the other things are made up of atoms, not what atoms themselves are made of.  they are not large, and they make up all matter

An atom is made up of a nucleus and revolving electrons. Inside the nucleus protons and neutrons are located. Thus the components of an atom are protons, electrons and neutrons. Thus, option A is correct.

An atom is the basic unit of every substances. Atoms combine together to form molecules, molecules then forms compounds and so on.

The inner core of an atom is called nucleus which contains positively charged particles namely protons and neutral particles neutrons. There are circular paths of fixed energy surrounding the nucleus.

The circular paths around the nucleus is called orbits through which the electrons are revolving. Electrons are negatively charged particles and they neutralize equal number of positive charges.

A neutral atom have equal number of protons and electrons and this number is called its atomic number. The sum of number of protons and neutrons is called the mass number.

Hence, an atom is made up of protons, electrons, and neutrons and option A is correct.

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Answer:

2.Diffusion

Explanation:

As we metabolize certain nutrients for the correct functioning of our cells, carbon dioxide is produced as a result. We need oxygen in order to metabolize them, so we need to have a system to incorporate it, and to eliminate the carbon dioxide produced.

This system is provided by the interaction between the respiratory system, which allows the enter of oxygen into the body and gets rid of the carbon dioxide, and the circulatory system, which acts transporting carbon dioxide and oxygen to and from the lungs, respectively.

The surface available for the gaseous exchange is enlarged by the pulmonary alveoli. The alveoli are the terminal aerial spaces of the respiratory system and the structures where the exchange between the air and blood is produced. Each alveolus is surrounded by a net of capillaries, where oxygen is freed from the hemoglobin and moves into the cells by diffusion. Carbon dioxide, diffuses out of the cells into the capillaries, where most of it dissolves in the plasma of the blood.

Answer:

An oxidising agent oxidises something else. Oxidation is loss of electrons (OIL RIG). That means that an oxidising agent takes electrons from that other substance.

Explanation:

Answer:

144cm²

Explanation:

Given dimensions:

     Length x breadth x thickness

        18cm  x   8cm    x    5cm

The widest part of this figure will be the face containing the length and the breadth.

The breadth is the width of the figure;

Area of the widest part  = length x breadth = 18cm x 8cm  = 144cm

The area of the widest part of the figure is 144cm²

The initial temperature of the metal = 35 °C

Heat can be formulated :

Q = m . c . ΔT

Q = heat, J

c = specific heat, J/g C

ΔT = temperature, °C

m = 20 g

c = 5 J/(g°C)

Q = 500 J

T₁ = 40 C

the initial temperature :

[tex]\tt \Delta t(T_2-T_1)=\dfrac{Q}{m.c}\\\\40-T_1=\dfrac{500}{20.5}\\\\40-T_1=5\\\\T_1=35^oC[/tex]

Answer:

For #3 I believe it's A

Explanation:

It can't be changed INTO a solid because it already is one.

Hope this helps!

Answer:

10 protons

Explanation:

The atomic number of an element is equal to the number of protons of the element. The atomic number of neon is 10. Therefore, neon contains 10 protons.

10 protons are in the nucleus of one atom of neon based on this information found in the Periodic Table.

The chemical elements are arranged in rows and columns in the periodic table, sometimes referred to as the periodic table of the elements. It is frequently used in physics, chemistry, and other disciplines and is frequently regarded as a symbol of chemistry.

The elements are organized in what is known as the periodic table. Columns and rows are used to organize the table. The horizontal rows are referred to as "periods," while the vertical columns are known as "groups."

Thus, The atomic number of an element is similar to the number of protons of the element. The atomic number of an element neon is 10. So, neon contains 10 protons.

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Answer:

Chemical weathering because the landform changed color

Explanation:

Answer: A) Chemical Weathering

Explanation:

I took the test :)

Answer:

Chemical

Explanation:

Answer:

D.A chemical that is not from living things

Answer:

1st one: crack

2nd: carefully

Explanation:

Answer:

Crack and then carefully

Explanation:

I just did it in edgen 2020

Answer:

let the number be x

so (x+6)/3 =5

x+6=15

x=9

2.1 x 10⁵⁶ atoms

The mole is the number of particles(molecules,atoms,ions) contained in a substance

1 mol = 6.02.10²³

number of atoms :

[tex]\tt 3.49\times 10^{32}\times 6.02\times 10^{23}=2.1\times 10^{56}[/tex]