Which of the following elements is used by your body? A) aluminum B) helium C) calcium D) all of the above

Answer:

Temperature

Explanation:

Answer:

community

Explanation:

Answer:

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

Answer:

In the gold crystal, the atoms are bonded by freely moving electrons. In the salt crystal, the atoms are bonded by the attraction of opposite electrical charges.

Explanation:

A.pex

A crystal of Gold (Au) has metallic bonding whereas a crystal of NaCl has ionic bonding.

Chemical bonding refers to the formation of a chemical bond between two or more atoms, molecules or ions to give rise to a chemical compound.

Ionic bonding occurs by transfer of electrons from one atom to another and is usually between a metal and a non metal atom. This type of bond is classically described as occurring when atoms interact with one another to either lose or gain electrons.

Metallic bonds are the chemical bonds that hold atoms together in metals.

Therefore, A crystal of Gold (Au) has metallic bonding whereas a crystal of NaCl has ionic bonding.

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Answer:

19.5g

Explanation:

Given parameters:

Volume of propane gas = 9.95L

Unknown:

Mass of propane gas =  ?

Solution:

To solve this problem, find the number of moles first.

    At STP;

        22.4L of gas makes up 1 mole

         9.95L of gas will have a [tex]\frac{9.95}{22.4}[/tex]    = 0.44mole

So;

   Mass of propane gas  = number of moles x molar mass

Molar mass of propane  = 3(12) + 8(1)  = 44g/mol

    Mass  = 0.44 x 44  = 19.5g

Answer:

European stability mechanism

Answer:

12 grams

Explanation:

Electrons do not contribute to mass. The proper unit to use is G

Answer:

H2SO4

Explanation:

Firstly,

2.056% hydrogen = 2.056g of H

32.69% Sulphur = 32.69g of S

65.26% oxygen = 65.26g of O

Next, we convert each mass into moles by dividing by their respective molar mass:

H = 1, S = 32, O = 16

H = 2.056/1 = 2.056mol

S = 32.69/32 = 1.021mol

O = 65.26/16 = 4.078mol

Next, we divide each mole value by the smallest mole value (1.021)

H = 2.056/1.021 = 2.01

S = 1.021/1.021 = 1

O = 4.078/1.021 = 3.99

Approximately the ratio of H to S to O is 2:1:4, hence, the empirical formula for H, S and O is H2SO4.

The empirical formula of a chemical compound is the simplest whole-number ratio of atoms present in a compound

The correct answer of the following is [tex]H_2SO_4[/tex]

The data is given as follows:-

We have to find the moles in the reaction.

The mas of the element is as follows:-

After solving the equation we get

[tex]H = \frac{2.056}{1} = 2.056mol\\\\S = \frac{32.69}{32} = 1.021mol\\\\O = \frac{65.26}{16} = 4.078mol[/tex]

Next, we divide each mole value by the smallest mole value (1.021)

[tex]H = \frac{2.056}{1.021} = 2.01\\\\S = \frac{1.021}{1.021} = 1\\\\O = \frac{4.078}{1.021} = 3.99[/tex]

The ratio of H to S to O is 2:1:4,

Hence, the empirical formula for H, S, and O is [tex]H_2SO_4.[/tex]

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The final volume : 807.69 cm³

Given

Initial volume : 840 cm³

Initial pressure : 750 mmHg

Final pressure : 780 mmHg

Required

The final volume

Solution

Boyle's Law  

At a fixed temperature, the gas volume is inversely proportional to the pressure applied  

[tex]\tt p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]

Input the value :

V₂=(P₁V₁)/P₂

V₂=(750 x 840)/780

V₂=807.69 cm³

Answer: [tex]C_3H_8+5O_2\rightarrow 3CO_2+4H_2O[/tex]

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation for combustion of propane will be :

[tex]C_3H_8+5O_2\rightarrow 3CO_2+4H_2O[/tex]

Answer:

combination, decomposition, single-replacement, double-replacement, and combustion.

Explanation:

Answer:

2.8 X 10-5s in standard notation is 28-5s

Explanation:

Multiply 2.8 by 10

Answer: here is your answer

Explanation:

The oxygen family consists of the elements that make up group 16 on the periodic table: oxygen, sulfur, selenium, tellurium, and polonium. These elements all have six electrons in their outermost energy level, accounting for some common chemical properties among them.

Answer:

they all have 6 valence electrons

Explanation:

all elements in group 16 have 6 valence electrons

The mole fraction of sulfuric acid : 0.073

Given

3.75 M sulfuric acid solution that has density of 1.230 g/mL

Required

The mole fraction

Solution

3.75 M = 3.75 mol/L

For 1 L solution :

mass of solution = 1230 g

mass Sulfuric acid : 3.75 mol x 98 g/mol=367.5 g

mass water = 1230-367.5 = 862.5 g

mol water = 862.5 : 18 g/mol= 47.92

mol total = 3.75 + 47.92 = 51.67

mole fraction of sulfuric acid :

= 3.75 : 51.67

= 0.073

Answer:

HOLY WOAH

Explanation:

YES

Answer:

True

Explanation:

Sometimes you will need to convert from grams to moles, or moles to grams

Answer:

Heredity is when you have gotten either physical or mental traits from your parents.

Inherited in Biology: Getting traits from your parents

Inherited outside Biology: is the practice of passing on private property, titles, debts, privileges, rights, and obligations upon the death of an individual.

Explanation:

Answer:

Electrons

Explanation:

Answer:

Electrons are not found in the nucleus for they are orbiting the atom.

Answer:

A. avoid talking to Anna altogether and stay out of her way

B. ask her manager for advice

C. check with Gary to see if there is any gossip about what's going on with Anna

D. take a curt approach of her own to show Anna how it feels

Explanation:

ANSWER: B.

We use roman numerals to indicate the oxidation state of metal atoms when naming compounds especially in the case of coordination compounds. It is a standard system of nomenclature.

Oxidation state of a species is the number electrons gained or lost. Oxidation state increases if electrons are lost from the atom and it will be decreased if electrons are gained.

For example, copper is in + 2 oxidation state in CuSO₄, thus it can be indicated as Cu(II). Copper can exists is +3 oxidation too. Thus the representation will be Cu (III).

All the transition metals like copper exhibit various oxidation state. So it is important to indicate in which oxidation state they are in a particular compound. In the compound Fe₂O₃, iron is in + oxidation state whereas in FeSO₄, it can be +2 . Thus it is important to note whether it is Fe (II) or Fe (III).

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Answer:

2CH4 ------> 3H2 + C2H2

Explanation:

The law of conservation of mass states that atoms can neither be created nor destroyed in a chemical reaction.

The implication of this law is that the number of atoms of each element on the reactant side must be equal to the number of atoms of each element on the product side.

This law is only obeyed by the reaction, 2CH4 ------> 3H2 + C2H2

There were eight atoms of H on the left hand side as well as the right and side of the reaction equation. There were two atoms of C on both the left and right hand sides of the reaction equation respectively. Hence, the law was obeyed here.

Answer:

Three main parts are Protons (pos charge) Neutrons (no charge) Electrons (negative charge) and the electron is found on the outside of the nucleus

Explanation:

Answer:

Grass

Explanation:

On a hot summers day, while barefoot Concrete normaly has heat absorbed into it. (Or on top) So when you go to Walk on it, It normally burns the heel.

Hope I helped and Have a great day!

brainliest?

Answer:

grass

Explanation:

the concrete has a higher specific heat capacity and is basically hotter than the grass which has a lower one

Answer:

Answer is on the pic

Explanation:

I hope it's helpful!

Answer:

C6H10Cl2

Explanation:

Convert mass % to mass

100g of the compound contains from each elements: 46,3g Cl; 47,05g C and 6,63g H

Molar mass

Cl = 35.5 g/mol

C = 12 g/mol

H = 1 g/mol

Find the number of moles:

Chlorine: 46.4g /35.5g/mol = 1,3 moles

Carbon: 47,05g/12 g/mol = 3,92 moles

hydrogen: 6,63g/1g/mol = 6,63 moles

Molar fraction:

Cl = 1,30/ 1,30 = 1

C = 3,92/ 1,30 = 3,01

H = 6,63/ 1.30 = 5,01

C3H5Cl = 76,5 g/ mol x 2  = 153 g/ mol

So multiply the molecular formula by two = C6H10Cl2

Answer:

See explanation

Explanation:

We know that surface area is an important determinant factor in the study of reaction rate. This is the reason why finely divided marble chips react faster than lumps of marble in the reaction between marble chips and dilute HCl.

Now imagine that i have a lump of marble and i have finely divided marble. Then i also have a solution of 0.5 M dilute HCl. If i introduce 1g of the lump  of marble into 250 ml solution of the 0.5 M HCl in one beaker and introduce 1g of finely divided marble into another 250 ml solution of 0.5 M HCl in a separate beaker, we will notice that the finely divided marble chips reacts faster as evidenced by the quicker effervescence of CO2 gas from the later compared to the former.

Hence, smaller marble chips reacts faster with dilute HCl than a lump of marble.

Answer:

yes the above given answer is absolutely correct I agree with u man on the above.

Answer:

here you go

Explanation:

5 elements and properties:

Boron- The chemical properties of boron are more similar to carbon and silicon than elements of its own group, although boron is more electron deficient. Boron has a high affinity for oxygen-forming borates, and reacts with water at temperatures above 100 °C to form boric acid and other boron compounds.

Carbon- As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. The most common isotope of carbon has 6 protons and 6 neutrons, and has an atomic mass of 12.0107 amu. Its ground state electron configuration is 1s22s22p2.

Nitrogen-  Nitrogen gas (chemical symbol N) is generally inert, nonmetallic, colorless, odorless and tasteless. Its atomic number is 7, and it has an atomic weight of 14.0067. Nitrogen has a density of 1.251 grams/liter at 0 C and a specific gravity of 0.96737, making it slightly lighter than air.

Oxygen- is the air you breath

Nickel- Nickel is a hard silver white metal, which forms cubic crystals. It is malleable, ductile, and has superior strength and corrosion resistance. The metal is a fair conductor of heat and electricity and exhibits magnetic properties below 345°C

5 compounds and properties:

Water - Formula: H2O = Hydrogen2 + Oxygen. ...

Hydrogen Peroxide - Formula: H2O2 = Hydrogen2 + Oxygen2 ...

Salt - Formula: NaCl = Sodium + Chlorine. ...

Baking Soda - Formula: NaHCO3 = Sodium + Hydrogen + Carbon + Oxygen3

Octane - Formula: C8H18 = Carbon8 + Hydrogen18

hope this helps