How many electrons must calcium lose to satisfy the octet rule?
Gain 2 electrons
Lose 2 electrons
Lose 40 electrons
Lose 20 electrons
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Answer:

nucleus

Explanation:

The nucleus holds all the other things, keeping them safe and confined.

Answer:

Nucleus

Explanation:

It contains DNA which contains a GENE which contains a CHROMOSOME so its NUCLEUS

Answer:

For the last few decades fires started by any type of smoking material has been the number one leading cause for household fire fatalities. It could just be that people luckily escape in time with cooking equipment fires, and smoking related fires just result in more deaths.

If the water vapor content remains the same and the temperature decreases, the relative humidity rises.

If the water vapor content remains the same and the temperature increases, the relative humidity falls.

This is because colder air doesn’t need as much moisture to become saturated as warmer air.

Hope this helps

B is the answer ,ammonium accepts a proton and becomes ammonium ion

Answer: The chemical name of the covalent compound [tex]P_4O_9[/tex]  is, tetraphosphorous nonaoxide.

Explanation:

A covalent compound is a compound where the sharing of electrons takes place between elements where both the elements are non-metals.

The naming of covalent compound is given by:

1. The less electronegative element is written first.

2. The more electronegative element is written second. Then a suffix is added with it. The suffix added is '-ide'.

3. If atoms of an element is greater than 1, then prefixes are added which are 'mono' for 1 atom, 'di' for 2 atoms, 'tri' for 3 atoms and so on.

Hence, the correct name for the compound [tex]P_4O_9[/tex] which is a covalent compound is, tetraphosphorous nonaoxide.

Answer:

An endothermic reaction takes in heat, but feels cold to the touch. An exothermic reaction gives off heat and feels warm to the touch because it is heating the outside objects.

Answer:

Explanation:

NH3 + H2O ⇌ NH4  + OH-

0.35                              0.35

-log[OH-] = -log0.35 = 0.46 = pOH

14 - 0.46 = 13.54 = pH

Answer:

It would have to be D, a bent shape

Explanation:

I just took the quiz

Answer:

THE SPECIFIC HEAT OF IRON IS 0.714 J/g °C

Explanation:

Heat  absorbed = 1000 J

Mass of the piece of iron = 14 g

Temeperature changes = ( 125-25)°C= 100°C

specific heat of iron = unknown

To find the specific heat of iron in the question use the formula of heat

Heat = mass * specific heat * temperature change

Specific heat = Heat / mass * temperature change

Specific heat = 1000 / 14 * 100

Specific heat = 1000 / 1400

Specific heat = 0.714 J/g °C

So therefore, the specific heat of iron is 0.714 J/g °C

Answer: 11 Electrons

Explanation:

We know that the atomic number of sodium is 11. This tells us that sodium has 11 protons and because it is neutral it has 11 electrons.

Answer:

The sodium atom is left with a full outermost electron shell with eight electrons, and the outermost shell of the other atom is full as well.

Explanation:

The sodium atom now has a positive electrical charge of plus 1, and the other atom has a negative charge of minus 1. The two opposite charges attract, and the two atoms now form the molecule of a compound.

Answer:

The empirical formula is same as the molecular formula = C6H10S2O

Explanation:

we start by dividing the percentage of each of the elements by their atomic mass

Carbon = 44.4/12 = 3.7

Hydrogen = 6.21/1 = 6.21

Sulphur = 39.5/32 = 1.234375

oxygen = 9.89/16 = 0.618125

That of oxygen is smallest so we divide all by that of oxygen

C = 3.7 / 0.618125 = 6

H = 6.21/ 0.618125 = 10

S = 1.234375/ 0.618125 = 2

Automatically, oxygen is 1

So the empirical formula is;

C6H10S2O

Let’s get its molecular formula. We multiply each of the subscript by the number;

(72 + 10 + 64 + 16)n= 162

162n = 162

n = 1

So the molecular formula is same as the empirical formula

Even though you asked for ONE WAY, I found some other good ways.

1. Thoroughly wash plastic soda bottles or milk jugs with warm, soapy water.

2. Store sealed containers in a dark, dry, and cool place.

3. If after six months you have not used the stored water, empty it from the containers and repeat steps 1 through 3 above.

Answer: The volume of a 0.10 mol/l HCl solution needed to neutralize 10 ml of a 0.15 mol/l LiOH solution is 15 ml

Explanation:

To calculate the volume of acid, we use the equation given by neutralization reaction:

[tex]n_1M_1V_1=n_2M_2V_2[/tex]

where,

[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]HCl[/tex]

[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is LiOH.

We are given:

[tex]n_1=1\\M_1=0.10mol/L\\V_1=?mL\\n_2=1\\M_2=0.15mol/L\\V_2=10mL[/tex]

Putting values in above equation, we get:

[tex]1\times 0.10\times V_1=1\times 0.15\times 10\\\\V_1=15mL[/tex]

Thus the volume of a 0.10 mol/l HCl solution needed to neutralize 10 ml of a 0.15 mol/l LiOH solution is 15 ml

Answer:

To separate an insoluble solid from a soluble solid:  Mixing the mixture with water, filtering out the insoluble solid, and then evaporating the water to isolate the soluble solid.

Explanation:

Answer:

In the oxide form, uranium can be disposed of as low-level radioactive waste at an approved disposal facility. Approximately 350,000 tons of anhydrous HF are used annually in the United States.

Explanation:

Answer: See below

Explanation:

1. To calculate the mass, you know you can convert by using molar mass. Since mass is in grams, we can use molar mass to convert moles to grams. This calls for the Ideal Gas Law.

Ideal Gas Law: PV=nRT

We manipulate the equation so that we are solving for moles, then convert moles to grams.

n=PV/RT

P= 100 kPa

V= 0.831 L

R= 8.31 kPa*L/mol*K

T= 27°C+273= 300 K

Now that we have our values listed, we can plug in to find moles.

[tex]n=\frac{(100kPa)(0.831L)}{(8.31kPa*l/molK)(300K)}[/tex]

[tex]n=0.033mol[/tex]

We use the molar mass of NO₂ to find grams.

[tex]0.033mol*\frac{46.005g}{1mol }=1.52 g[/tex]

The mass is 1.52 g.

2. To calculate the temperature, we need to use the Ideal Gas Law.

Ideal Gas Law: PV=nRT

We can manipulate the equation so that we are solving for temperature.

T=PV/nR

P= 700.0 kPa

V= 33.2 L

R= 8.31 kPa*L/mol*K

n= 70 mol

Now that we have our values, we can plug in and solve for temperature.

[tex]T=\frac{(700kPa)(33.2L)}{(70mol)(8.31 kPa*L/molK)}[/tex]

[tex]T=40K[/tex]

The temperature is 40 K.

Answer:

potassium is likely to be harder

Explanation:

because whenan atom loss electron they can form particle ion acquare stable a arrangement that loos electron can transfer to another which that also to acquaire stable

Answer: Thus [tex]CH_3CH(OH)CH_3[/tex] is a secondary alkanol.

Explanation:

Alkanol are compounds which contains carbons bonded by single bonds and contains hydroxy (-OH) as functional group.

Primary alkanol are those compounds which contain hydroxyl group attached a carbon which is further attached to a single carbon atom. Example: [tex]CH_3CH_2CH_2OH[/tex] and [tex]CH_3CH_2CH_2CH_2OH[/tex]

Secondary alkanol are those compounds which contain hydroxyl group attached to a carbon which is further attached to two more carbon atoms.Example: [tex]CH_3CH(OH)CH_3[/tex]

Tertiary alkanol are those compounds which contain hydroxyl group attached to a carbon which is further attached to three more carbon atoms. Example: [tex]C(CH_3)_3OH[/tex]

Thus [tex]CH_3CH(OH)CH_3[/tex] is a secondary alkanol.

Answer:

Titrations. Because a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end of a titration. When selecting an indicator for acid-base titrations, choose an indicator whose pH range falls within the pH change of the reaction.

Hope it helped!!

Answer:

0.046 M

Explanation:

Molarity = mol solute/ L solution = 0.23 mol/ 5 L = 0.046 mol/L = 0.046 M

Answer: Significant figures in a measurement are all measured digits, and one estimated digit

Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.

Explanation:

Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy or precision is known as significant digits.

The significant figures of a measured quantity are defined as all the digits known with certainty and the first uncertain or estimated digit.

Rules for significant figures:

1. Digits from 1 to 9 are always significant and have infinite number of significant figures.

2. All non-zero numbers are always significant.

3. All zero’s between integers are always significant.

4. All zero’s preceding the first integers are never significant.

5. All zero’s after the decimal point are always significant.

The true statements are

Significant figures in measurement are all measured digits, and one estimated digit

Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.

The following information should be considered:

Learn more: https://brainly.com/question/1979431?referrer=searchResults

mg reacts with the acid and produce visible bubbles of hydrogen gas. they will produce audible pops as the hydrogen ignites. ... Hydrochloric acid is a corrosive liquid. Hydrogen gas is explosive.

Answer:

Here's what I get  

Explanation:

The molecules of a substance attract each other.

They are also in constant motion.

Their kinetic energy increases with the temperature.

1. Solids

If the temperature is low enough, the molecules will have little kinetic energy.

They will not be able to escape the attractions of their neighbours, so they will be fixed in place in a crystalline array.

All they can do is vibrate about their position in the array.

The substance will be a solid.

2. Liquids

If the temperature is higher, the molecules will have enough kinetic energy to slide past each other, but not enough to escape the attractions of nearby molecules.

The substance will be a liquid.

3. Gases

If the temperature is high enough, the molecules will have enough kinetic energy to escape from the surface and fly off into space.

The molecules will on average so far apart that they won't feel the attractions of others.

When they do collide, they will have energy to bounce off each other rather than stick together.

The substance will be a gas.

Answer:

base

Explanation:

carbonic acid - H2CO3 - is a weak acid. Therefore, HCO3 itself is its conjugate base. The Na(sodium) ion is neutral.

This means that NaHCO3 is a base. (a weak one)

Answer: SI prefixes are used to form decimal multiples and submultiples of SI units. They should be used to avoid very large or very small numeric values.

Explanation: ^^^

Answer:

336.1 g of PbS precipitate

Explanation:

The equation of the reaction is given as;

Na2S(aq) + Pb(NO3)2(aq) ----> 2NaNO3(aq) + PbS(s)

Ionically;

Pb^2+(aq) + S^2-(aq) -----> PbS(s)

Number of moles of sodium sulphide= concentration of sodium sulphide × volume of sodium sulphide

Number of moles of sodium sulphide= 0.780 × 1.5 = 1.17 moles

Number of moles of lead II nitrate= concentration of lead II nitrate × volume of lead II nitrate

Number of moles of lead II nitrate= 3.31× 1.00= 3.31 moles

Then we determine the limiting reactant. The limiting reactant yields the least amount of product.

Since 1 moles of sodium sulphide yields 1 mole of lead II sulphide

1.17 moles of sodium sulphide also yields 1.17 moles of lead II sulphide

Hence sodium sulphide is the limiting reactant.

Thus mass of precipitate formed= amount of lead II sulphide × molar mass of sodium sulphide

Molar mass of lead II sulphide= 287.26 g/mol

Mass of lead II sulphide = 1.17 moles × 287.26 g/mol

Mass of lead II sulphide= 336.1 g of PbS precipitate