Which of the following characteristics indicates that an atom is unstable?

Answer:

6 days

Explanation:

The following data were obtained from the question:

Original amount (N₀) = 100 mg

Amount remaining (N) = 6. 25 mg

Time (t) = 24 days

Half life (t½) =?

Next, we shall determine the decay constant. This can be obtained as follow:

Original amount (N₀) = 100 mg

Amount remaining (N) = 6. 25 mg

Time (t) = 24 days

Decay constant (K) =?

Log (N₀/N) = kt / 2.303

Log (100/6.25) = k × 24 / 2.303

Log 16 = k × 24 / 2.303

1.2041 = k × 24 / 2.303

Cross multiply

k × 24 = 1.2041 × 2.303

Divide both side by 24

K = (1.2041 × 2.303) / 24

K = 0.1155 /day

Finally, we shall determine the half-life of the isotope as follow:

Decay constant (K) = 0.1155 /day

Half life (t½) =?

t½ = 0.693 / K

t½ = 0.693 / 0.1155

t½ = 6 days

Therefore, the half-life of the isotope is 6 days

Answer:

Sodium is an alkali metal so it needs to lose an electron to fill it's outer shell.

That is an ion. When an element loses or gains an electron but in this case, sodium needs to lose an electron.

The diagram shows 5 eletctron in the outermost shell of Nitrogen atom out of which 3 electrons are involved in the bond formation with 3 Hydrogen atoms.

The type of bond in ammonia is Covalent.

Covalent bond is the bond formed by mutual Sharing of electrons by both the atoms taking part in the bond formation.

Nitrogen has 5 valence electrons of which only 3 are shares with the 3 atoms of hydrogen (one electron shares with one atom of hydrogen)

Hence, type of  bond in ammonia is covalent.

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Answer:

2. reasoning

Explanation:

PLS GIVE BRAINLIEST

Answer:

solution:-a homogenous mixture of two or more substances in relative amounts that can be varied continuously up to what is called the limit of solubility.

solute:-is a substance, usually a solid, that is dissolved in a solution, which is usually a liquid.

solvent:-substance, ordinarily a liquid, in which other materials dissolve to form a solution.

polar molecule:-is a molecule in which one end of the molecule is slightly positive, while the other end is slightly negative.

Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.

concentration refers to the amount of a substance in a defined space.

Explanation:

Answer: B

Explanation:

B

correct form of question is

Explain the difference between Carbon-12 and Carbon-14. Which version Carbon do you believe is the most stable? Why? What information could help you confirm your prediction?

Answer:

Carbon has three isotopes those are carbon- 12 , carbon - 13 , carbon-14 among these only C-12 and C-13 are stable while C-14 is radioactive.

C-12 has 6 protons and 6 neutrons , C-14 has 6 protons and 8 neutrons. Atoms with equal number of protons and electrons are generally stable however C-12 and C-14 have 6 electrons but due to excess neutrons present in C-14 makes it undergo radioactivity therefore it is unstable.

Metals have shiny surface by which they reflect light. The two properties which can be measured from the metallic shine and scratches in a metal are its luster and hardness.

Metals are electropositive elements conducts thermally and electrically. Almost all metals shows a shining property when they reflect light and it is called metallic luster.

Hardness of a metal can be a measure how much the metals resists scratches. Very hard metals do not form powders on scratching. Less hard metals may effect by scratches.

More hard and shining metals have various applications such as in construction fields, optoelectronic devices, thermal coatings and corrosion resistant products.

Hence, option a and b, hardness and luster can be measured from the scratches and metallic shining respectively.

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Your question is incomplete, but most probably your full question was:

If a mineral has a metallic shine and scratches, which of its properties are being measured?

choose the two correct answers.

a. luster

b. hardness

c. magnetism

d. cleavage

Answer:

The answer should be Oppositely charged ions attract. So A.

Explanation:

Answer:

have the same number of protons

Explanation:

Atoms of the same element will always have the same number of protons.

Protons are the positively charged particles in an atom which are located in the nucleus.

Answer:

it it the first law

Explanation:

Answer:it is an example of Newton’s 3rd law

Explanation:the balloon had a reaction

Answer:

the line represents the condition where pressure and heat have the same effects.

Answer: C) The melting point of a substance at a specific pressure.

Answer:

Opt for foods low in sugar and fat and high in fiber.

Explanation:

Any noncitrus fruits, oatmeal, leafy green vegetables, ginger is excellent for heartburn and stomachaches.

Hey there!

Molar mass SO₂ = 64.066 g/mol

Therefore:

1 mole SO₂ -------------------- 64.066 g

(moles SO₂ ) ??---------------- 5.0 g

( moles SO₂) = 5.0 * 1 / 64.066

(moles SO₂) = 5.0 / 64.066

moles = 0.0780 moles of SO₂

Hope this helps!

Answer:

Basically, the more hot the state is, the more kinetic energy it will have. This means that answer D. would be right, as it goes from coldest to hottest states!

Answer:

The answer is D. solid, liquid, gas, plasma

Explanation:

Answer:

i think it might be separation by density

Explanation:

Answer:

B: Sort by density

Btw im not copying the person above me. I am 98% Sure its density

Answer:

^=E9>*t

Explanation:

Answer is D formation of gas.

Explanation: I hope that helped/have a great day.

Answer:

I think it is D.

Explanation:

Answer:

b

Explanation:

Answer:

Physical change

Explanation:

while the wax is melting its still wax no chemical change

hope this helps :3

if it did pls mark brainliest

Answer:

the atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope

Explanation:

Average atomic mass = f1M1 + f2M2 + … + fnMn where f is the fraction representing the natural abundance of the isotope and M is the mass number (weight) of the isotope. The average atomic mass of an element can be found on the periodic table, typically under the elemental symbol.

Answer:

he atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.

Answer:

Diffusion is faster at higher temperatures because the gas molecules have greater kinetic energy. Effusion refers to the movement of gas particles through a small hole. Graham's Law states that the effusion rate of a gas is inversely proportional to the square root of the mass of its particles

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:

option A is the ans i think so

If an unknown solution has pH of 9 the solution is classified as a base as it has larger concentration of hydroxyl ions.

According to the Arrhenius concept, base is defined as a substance which yields hydroxyl ions on dissociation.These ions react with the hydrogen ions of acids to produce salt in an acid-base reaction.

Bases have a pH higher than seven as they yield hydroxyl ions on dissociation.They are soapy in touch and have a bitter taste.According to the Lowry-Bronsted concept, base is defined as a substance which accepts protons .Base react violently with acids to produce salts .Aqueous solutions of bases can be used to conduct electricity .They can also be used as indicators in acid-base titrations.

They are used in the manufacture of soaps,paper, bleaching powder.Calcium hydroxide ,a base is used to clean sulfur dioxide gas while magnesium hydroxide can be used as an antacid to cure acidity.

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Answer:

the flow of the water pushed the mud around the anchor

Explanation:

The information regarding the mud should be explained below:

The following information should be considered:

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