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5. Sodium-24 has a half-life of approximately 15 hours. If only one-eighth of the sodium-24 remains, about how much time has passed?
A. 15 hours
B. 30 hours
C. 45 hours
D. 60 hours

Gravity, as a fundamental force of nature, is influenced by several factors. The following are some of the key factors affecting gravity:

Answer:

Physical properties are defined as the properties which can be observed without changing its chemical composition.

For example: color, volume, and molecular weight.

Chemical properties are defined as the properties which can be observed only after changing chemical identity of the substance.

For example: reactivity, toxicity, and flammability.

The fundamental differences between physical and chemical properties are as follows:

Answer:

Chemical properties are related to chemical bonds of the substance while physical properties are not.

In chemical properties, chemical identity of substance changes while physical properties do not have any change.

Chemical properties predict the reaction of substance while physical properties only describe the appearance of the substance.

Explanation:

3.125g

Explanation

2.4 minutes = 1 half life

so 12 minutes = 5 half lives (12/2.4)

100g/2 = 50g (1 half life)

50g/2 = 25g (2 half lives)

25g/2 = 12.5g (3 half lives)

12.5g/2 = 6.25g (4 half lives)

6.25g/2 = 3.125g (5 half lives)

Answer:

true

Explanation:

It's true man..............true.........

Answer:

0.24 M

Explanation:

Step 1: Write the balanced neutralization reaction

NaOH + HCl ⇒ NaCl + H₂O

Step 2: Calculate the reacting moles of NaOH

17.89 mL (0.01789 L) of 1 M NaOH react.

0.01789 L × 1 mol/L = 0.01789 mol

Step 3: Calculate the moles of HCl that reacted with 0.01789 moles of NaOH

The molar ratio of NaOH to HCl is 1:1. The moles of HCl that reacted are 1/1 × 0.01789 mol = 0.01789 mol.

Step 4: Calculate the molar concentration of HCl

0.01789 moles are in 75 mL (0.075 L) of HCl,

[HCl] = 0.01789 mol/0.075 L = 0.24 M

Answer:

6 hours

Explanation:

If it is traveling at 50mph and needs to reah 300 miles, to figure this problem out you would want to divide 300 by 50 to get 6 hours. So it will take six hours until the car travels 300 miles

Hope this helps.

Answer: A car travels at a rate of 50 miles per hour. how long will it take the car to travel 300 miles?

Explanation: .

Applying the distance formula:

d = rt

where

d is distance (300 miles)

r is rate (50 mph)

t is time (hours)

.

300 = 30t

300/30 = t

10 hours = t

Answer:

190n

Explanation:

190 190 and because it is easy to understand if you didn't understand my answer ask any man

A. Automobile exhaust. Two-thirds of the sulfur dioxide (SO2) that pollutes the air is produced by automobile exhaust.

Automobile exhaust refers to the emissions released by vehicles, primarily from the combustion of fuel in their engines. It is a mixture of gases, particles, and other pollutants that are expelled from the tailpipe of a vehicle during its operation.

The composition of automobile exhaust can vary depending on factors such as the type of fuel used (gasoline, diesel, etc.), engine design, and emission control systems. However, some common components of automobile exhaust include:

Carbon Dioxide (CO2): A greenhouse gas that is a byproduct of the combustion of fossil fuels. It contributes to climate change.

Carbon Monoxide (CO): A colorless, odorless gas that is formed when carbon-based fuels are incompletely burned. It is poisonous and can be harmful in high concentrations.

Nitrogen Oxides (NOx): These include nitrogen monoxide (NO) and nitrogen dioxide (NO2). They are formed when nitrogen in the air reacts with oxygen at high temperatures in the engine. NOx emissions contribute to air pollution and the formation of smog.

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Yes, the elements that will be formed in a fusion reaction can be predicted by looking at the combining nuclides.

A nuclear reaction is one in which the nucleus of elements undergo rearrangement to form new nuclei and release energy.

Mass and charge of reactant and product nuclides are conserved in a nuclear reaction.

This implies that we can look at the reactant nuclides and predict the products of the nuclear fusion . This can be done by studying the combining nuclides and taking into cognizance, the balance of mass and charge on both sides of the nuclear reaction equation.

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Answer: Yes it is possible

Explanation: The element that is formed in a fusion can be predicted by looking at the combining elements or nuclides in this case it would be the hydrogen isotopes

Explanation:

the experiment conducted is the student adds sugar to a cup of iced tea and a cup of hot tea. She notices that the time needed for the sugar to dissolve in each cup is different. She thinks this has something to do with the temperature of the tea

hypothesis: If the student puts the sugar in both glasses of tea, then the sugar in the hot tea should dissolve quicker.

The reaction is a decomposition reaction

The given reaction is not a redox (oxidation-reduction) reaction because there is no change in oxidation number of any of the atoms in the reaction.

Also, it is not a double replacement reaction as there are no ions or compounds being exchanged between the reactants.

This is a decomposition reaction, where one compound (CF4) is breaking down into two simpler substances (C and F2).

A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances. In a decomposition reaction, a compound is broken down into its constituent elements or simpler compounds.

The reaction can be represented by a chemical equation where the reactant is the compound that is breaking down, and the products are the simpler substances formed as a result of the reaction.

The general formula for a decomposition reaction is:

AB → A + B

where AB is the compound that is decomposing, and A and B are the simpler substances formed as a result of the reaction.

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The concentration of oxygen in the atmosphere at standard conditions (P° = 1013.25 hPa, 1.00 atm) and 25 °C is approximately 10.94 mol/m³ and 217.9 g/m³.

To calculate the concentration of oxygen in mol/m³, we need to convert the given mixing ratio (20.95%) into a decimal fraction. The mixing ratio represents the proportion of a particular gas in the atmosphere. Therefore, 20.95% can be written as 0.2095.

Next, we use the ideal gas law to calculate the concentration in mol/m³. The ideal gas law equation is PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

At standard conditions (P° = 1013.25 hPa or 1.00 atm) and 25 °C (298 K), we can assume the volume is 1 m³. Rearranging the ideal gas law equation, we get n = PV/RT.

Substituting the values into the equation, n = (1013.25 hPa * 1 m³) / (0.0821 * 298 K), we find the number of moles of oxygen.

Finally, to calculate the concentration in g/m³, we multiply the number of moles by the molar mass of oxygen (32 g/mol).

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Answer:

Models 1 and 2 would be in the same group.

Explanation:

They have the same amount of valence electrons. Valence electrons are electrons in the outermost electron cloud. This means they have the same properties, therefore are in the same Group on the periodic table.

At constant temperatures, the simplest approach to reduce the volume of a gas is to raise its pressure. So, at 700 bar, or 700 times normal atmospheric pressure, hydrogen has a density of 42 kg/m3, compared to 0.090 kg/m3 at normal pressure and temperature.

Hydrogen decreases metal oxides in the reactivity series below. That is, hydrogen can only decrease the oxides of metals that are less reactive than hydrogen itself.

High-Temperature Water Splitting: Chemical processes that split water to make hydrogen are fueled by high temperatures generated by solar concentrators or nuclear reactors.

The oxidation number of hydrogen gas is 0, but the oxidation state of hydrogen atoms in water is +1. As a result, the hydrogen atom has been oxidized. It acts as a reducing agent.

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Answer:

dissolving

Explanation:

Answer:

dissoliving

Explanation:

salt and sugar are both soluble

Answer:6.7103x10^5 km

Explanation:

The planet is at a distance of about 6.71030 ×10⁵ km. Therefore, option (c) is correct.

Scientific notation is a way of representing a quantity as a number having significant digits that are necessary for a specified degree and multiplied by ten to the power.

The general form of scientific notation can be written as \(N \times 10^{a}\).

A significant digit is that digit in a number which adds to its precision. A significant includes all nonzero numbers, zeros between significant digits, and zeros represent to be significant while leading and trailing zeros are not significant digits as they exist only to represent the scale of number.

Given, using the scientific notation method we can write the scientific notation of the distance of 671,030 km.

The number 671,030 km can also be written as 6.71030 ×10⁵ km.

Therefore, the correct way to write this distance in the scientific notation of  671,030 km is 6.71030 ×10⁵ km.

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Answer:

The answer is

A- H

B- C

Explanation:

Answer:

The answer is

A- H

B- C

Explanation:

Answer:

a = 4

b = 3

Explanation:

SOLUTION :-

Balance it by using 'hit & trial' method , and you'll get the answer :-

2Fe₂O + 3C → 4Fe + 3CO₂

⇒ a = 4 ; b = 3

VERIFICATION :-

In reactant side of equation :-

In product side of equation :-

Number of atoms of each element is equal in both reactant & product side of equation. Hence , the equation is balanced.

Should be aware of the R/S configuration CIP rules' priority ranking. A) -CECH (option A).

Stereocenter. An atom that is connected to four different atoms is known as a stereogenic center, and simply a stereocenter. A stereocenter, also known as a stereogenic center, is a particle group in which any two groups can be exchanged to produce a stereoisomer.

When a carbon is joined to four other atoms, or groups of atoms, chiral centers are created. Although they are mirror reflections of one another, chiral compounds are not identical. Stereocenters are also chiral centers, although not usually the other way around.

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Answer:

Magnesium Flouride is a ionic compound and thus has a giant lattice structure. Its ions are held together in this lattice by strong electrostatic forces of attraction. A large amount of energy is needed to overcome the strong electrostatic forces of attraction between the Mg2+ ions and the F- ions to separate the ions. Hence Magnesium fluoride has a very high melting point.

Answer:

True

Explanation:

they have the same number of protons but different number of neutrons which results in a different mass

I would greatly appreciate if you can give this the brainliest answer crown!

Answer:

500976 J

Explanation:

Mass of Oxygen= 2352.00 g/1000 = 2.352 Kg

Heat of vaporization of oxygen = 213 kJ kg − 1

The heat of vaporization of a substance refers to the amount of heat required to  boil  1  Kg of a given substance at its boiling point.

Thus energy required to boil 2.352 Kg of oxygen = 2.352 Kg * 213 kJ kg − 1  = 500.976 KJ

To convert this to J = 500.976 KJ * 10^3 = 500976 J

The effect on the amount of gas produced is that if the experiment is repeated using 0.35 grams of potassium is that less amount of hydrogen gas is liberated.

When  potassium reacts with water it liberates hydrogen gas and potassium hydroxide is formed.

\(2K+3H_2O\rightarrow2H_2+2KOH\)

When lithium reacts with water it liberates hydrogen gas and lithium hydroxide is formed.

\(2Li+3H_2O\rightarrow2H_2+2LiOH\)

Moles in case of each reaction can be calculated by the formula ,

                     n=W/M

where W =mass and M=molar mass

therefore, moles of potassium  are ,0.35 g/39=0.0089

and moles of lithium are,0.35 g/6.9=0.0507

Since the amount of moles produced when lithium metal is used is more as compared to potassium ,lithium will produce more gas.Thus,on replacing lithium with potassium less gas will be produced.

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it's an ionic bond

btw i love your profile picture never understand is one of my favorites

The positively charged center in an atom is called as Nucleus. It is made up of positively charged protons and neutral sub-atomic particle called as neutrons.

What is meant by protons ?

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Answer:

4

Explanation:

Speed=Distance/time, so 20/5 divide time divided by distance. so the answer is 4.

The speed of Haley the hummingbird is 4 m/s.

From the question,

We are to calculate the speed of Haley the hummingbird

Speed is given by the formula

\(Speed =\frac{Distance\ traveled}{Time\ taken}\)

From the given information,

The hummingbird can fly from a pansy flower to a hibiscus flower 20 meters away in 5 seconds.

That is,

The bird can cover a distance of 20 meters in 5 seconds.

Therefore,

Speed of the hummingbird = \(\frac{20}{5}\)

Speed of the hummingbird = 4 m/s

Hence, the speed of Haley the hummingbird is 4 m/s.

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Answer:

pretty sure it's the second option, sorry if I'm wrong..

Explanation:

Answer:

Explanation: Aluminium heats very quickly and easily reacts with acidic vegetables and foods, so it is advisable to avoid cooking in such utensils. These chemical reactions affect your immune system.

Answer:

high less air cause there is no trees and lower is the same

Explanation: