How do I do this problem???

Answer:

3.7

Explanation:

Significant figures:

All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

Leading zeros are not consider as a significant figures. e.g. 0.007 in this number only one significant figure present which is 7.

Zero between non zero digits are consider significant such as  1004 consist of four significant figures.

The zeros at the right side such as 4500 are also significant. There are four significant figures are present.

When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.

When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.

Now we will calculate the difference between 7.69 and 4.0.

7.69 - 4.0 = 3.69

In given values 4.0 have less number of decimal places thus result must have only one decimal places. So we would round the result.

3.7

what are your steps to this from the lesson

Answer:

the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

Answer:

The atomic mass is the mass of an atom.

Explanation:

Answer:

The answer is 3and 5/9 multiplied by 20 which is about one hour and  14 ,inutes

Explanation:

Answer:

me

Explanation:

Draw the Lewis dot structure for each atom of the compound to show how many valence electrons are present in each atom. For example, the calcium atom in calcium chloride, CaCl2, has two valence electrons, and the chlorine atoms have seven valence electrons each.

Answer:

Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.

Explanation:

google

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question we have

[tex]density = \frac{38.6}{2} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

1.28g

Explanation:

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Answer:

1. The balanced equation is given below:

Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)

2a. H is oxidized.

2b. Sn is reduced.

Explanation:

1. Balanced equation for the reaction between tin (Sn) metal and aqueous hydrochloric acid (HCl) to produce tin(II) chloride (SnCl₂) and hydrogen gas (H₂).

This is illustrated below:

Sn (s) + HCl (aq) –> SnCl₂ (aq) + H₂ (g)

There are 2 atoms of Cl on the right side and 1 atom on the left side. It can be balance by putting 2 in front of HCl as shown below:

Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)

Now, the equation is balanced

2. Determination of the element that is oxidize and reduced.

This can be obtained as follow:

We shall determine the change in oxidation number of each element.

NOTE:

a. The oxidation number of H is always +1 except in hydrides where it is –1.

b. The oxidation state of Cl is always –1.

Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)

For Tin (Sn):

Sn = 0

SnCl₂ = 0

Sn + 2Cl = 0

Cl = – 1

Sn + 2(–1) = 0

Sn – 2 = 0

Collect like terms

Sn = 0 + 2

Sn = +2

Therefore, the oxidation number of Tin (Sn) changes from 0 to +2

For H:

H = +1

H₂ = 0

The oxidation number of H changes from +1 to 0

For Cl:

Cl is always –1. Therefore no change.

Summary:

Element >>Change in oxidation number

Sn >>>>>>>From 0 to +2

H >>>>>>>>From +1 to 0

Cl >>>>>>>No change

Therefore,

Sn is reduced since its oxidation number increased from 0 to +2.

H is oxidized since it oxidation number reduced from +1 to 0

The balanced chemical equation for the reaction is

Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)

and the element that oxidized is tin (Sn) while the element that is reduced is hydrogen (H)

The balanced chemical equation for the reaction where tin metal reacts with aqueous hydrochloric acid to produce tin(II) chloride and hydrogen gas is

Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)

From the equation,

The element that is oxidized is tin (Sn), because the oxidation state of Sn increased from 0 to +2

The element that is reduced is hydrogen (H), because the oxidation state of H decreased from +1 to 0.

Hence,

The balanced chemical equation for the reaction is

Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)

and the element that oxidized is tin (Sn) while the element that is reduced is hydrogen (H).

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Answer:

See explanation.

Explanation:

1. There are 8 electrons. Elements that end with 2p orbitals are in the 2nd period (aka row) of the periodic table. Elements that have 4 electrons in 2p are in the 16th group (aka column) (column 16 may also be referred to as 6A) of the periodic table. So looking at row 2, column 16, we can see that the first diagram is of O, Oxygen.

2. 8 electrons. This is the same diagram as the one above.

3. 13 electrons. Elements ending with 3p are in period 3. Elements with 1 valence electron in a p orbital are in group 13 (aka group 3A).

4. 7 electrons. We already know 2p is period 2. 3 valence electrons in a p orbital means that it is in group 15/group 5A.

I did not write the answers for #3 and 4 but they can be easily found on a periodic table with the info I gave.

The elements given the above orbital diagrams are as follows:

Oxygen

Oxygen

Aluminum

Nitrogen

In first case,

There are total 8 electron and the electronic configuration is 1s2 2s2 2p4. The element which end up with 2p configuration belongs to 2nd period. It have four electron in their outermost shell so, it belongs to 16th group, So the element is Oxygen.

In the same way we will find the elements for rest of the cases.

Thus, we reach to the conclusion that the elements given the above orbital diagrams are as follows:

Oxygen

Oxygen

Aluminum

Nitrogen

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Answer:

Yes the air particles have mass

Explanation:

Air is mater: it has weight and occupies space. For it to have weight, it has to have a mass. The mass would however be determined by how much volume of air is trapped in the container, but nevertheless, the mass of the air can be obtained.

We also notice that if the container is "popped", the mass of air escapes through one way by the weight exerted on it.

I hope this was helpful.

Answer:

Yes the air particles have mass

Explanation:

You can tell that if the container is pooped open the mass of air escapes

Answer:

Explanation:

If the energy of an atom is increased, an electron in the atom gets excited. To go back to its ground state, the electron releases energy. The energy of the light released when an electron drops in energy level is the same as the difference in energy between the two levels.

Viewed simply, electrons are arranged in shells around an atom’s nucleus. Electrons closest to the nucleus will have the lowest energy. Electrons further away from the nucleus will have higher energy. An atom’s electron shell can accommodate 2n2 electrons (where n is the shell level).

In a more realistic model, electrons move in atomic orbitals, or subshells. There are four different orbital shapes: s, p, d, and f. Within each shell, the s subshell is at a lower energy than the p. An orbital diagram is used to determine an atom’s electron configuration.

There are guidelines for determining the electron configuration of an atom. An electron will move to the orbital with lowest energy. Each orbital can hold only one electron pair. Electrons will separate as much as possible within a shell.

In an atom, electrons are arranged in shells that surround the nucleus, with each successive shell moving further away from the nucleus.

In physics, an energy level is any discrete value from a set of total energy values for a subatomic particle confined by a force to a limited space or for a system of such particles, such as an atom or a nucleus.

Energy levels are fixed distances from an atom's nucleus where electrons can be found. Electrons are tiny, negatively charged particles that move around an atom's positive nucleus. The steps of a staircase represent energy levels.

Around the nucleus, electrons are arranged in different shells. Each successive shell can only hold so many electrons. First, the innermost shell is filled. This shell can only contain two electrons.

Thus, this way, the electrons are arranged.

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Answer:

1. Solid Definition: firm and stable in shape; not liquid or fluid.

Example: A hard kitchen countertop.

2. Crystalline Solid Definition: Crystalline solids consist of atoms, ions and molecules arranged in definite and repeating three-dimensional patterns in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

Example: Salt, diamonds

3. Amorphous Solid Definition: an amorphous or non-crystalline solid is a solid that lacks the long-range order that is characteristic of a crystal.

Example: rubber, plastic, and gels

4. Liquid Definition: A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a constant volume independent of pressure. As such, it is one of the four fundamental states of matter, and is the only state with a definite volume but no fixed shape.

Example: Water, juice, rain

5. Surface Tension Definition: the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.

Example: Walking on water: Small insects such as the water strider can walk on water because their weight is not enough to penetrate the surface.

Explanation:

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Answer:

The physical properties of minerals are related to their chemical composition and bonding. Some characteristics, such as a mineral's hardness, are more useful for mineral identification.

Explanation:

Answer:

Explanation:

mineral properties are what it is made if the characteristics are what it looks like. Like is it shiny, hard, smooth. those are characteristics.

Answer: argon

What must happen to a sulfur atom in order for it to have an electron arrangement similar to that of a noble gas? Answer: The noble gas closest to sulfur is argon. A sulfur atom gains two electrons to have an electron arrangement similar to that of argon.

Explanation:

Answer:

Two Lithium ions and one carbonate ion

Explanation:

Let us look at this equation;

Li2CO3(s) ------->2Li^(aq) + CO3^2-(aq)

We can see that each unit of Li2CO3 has two lithium ions and one carbonate ion.

Let us not forget that Li has a valency of 1 while carbonate ion has a valency of 2. Exchange of valencies gives the final formula of the compound.

Answer:

Two Lithium ions and one carbonate ion

Explanation:

Answer:

15660.712J

Explanation:

Q = m × c × del T

Q(energy) = ?

m (mass) = 98.5g

c = 4.184J

del T = 75-37 = 38 °C

Q = 98.5 × 4.184 × 38

Q = 15660.712 J

Answer:

It's Clean?

Explanation:

Answer:

=0.00123

Explanation:

Look at the attachments below

Hope this helps (:

Answer:

0.00123

Explanation:

Standard notation is the normal way of writing numbers. Examples include 1, 2, and 10. The number 1.23 x 10^-3 is written in scientific notation. The decimal goes after the first nonzero integer and it is multiplied by a power of 10. The power or exponent attached to the 10 tells you how many places over you need to move the decimal to get back into scientific notation. Examples include 1.00 x 10^2 (representing 100 in standard form because you would move the decimal two places to the right.), 2.0 x 10^1 (representing 20 in standard form because you would move the decimal one place to the right), and 3.0 x 10^-4 (representing 0.0003 in standard form because you would move the decimal four places to the left since it is a negative exponent).

The negative (-3) exponent in 1.23 x 10^-3 indicated to move the decimal three places to the left. If it was positive, you would move it three places to the right.

In 1.23 x 10^-3 move the decimal to the left 1 place to get:

0.123

two places to get:

0.0123

and a third place to get:

0.00123

The final answer is 0.00123

Answer:

It might be e=FCA

Explanation:

Answer:

Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.

Hope it helps

The state change occurs when the glass melts.

The matter is anything that has mass and occupies space.

The different states of matter are solid, liquid, gas, and plasma.

The properties of the different types of matter can be understood by looking at the arrangement of molecules.

When a solid substance is heated beyond its melting point, it changes its state from solid to liquid.

When liquid is heated beyond its vaporizing point, it changes its state from liquid to gas.

Solids are closely packed and have a definite shape and size.

Liquids are loosely packed and take up the space of the container.

Gas has high intermolecular spacing and the gases are not rigid.

Ground glass is melted under light heat and poured into molds.

Recycling glass involves changing the state of glass from solid to liquid state.

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Answer:

mechanical or kinetic eg hammer and nails

Answer:

b and then c

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Answer:

The net force is 0

Explanation:

because both people on either side are pulling the rope with the same force