Pls help I will give u points pls

Answer:

Stopwatch

Stopwatch is a time measuring tool.

Answer:

YES!

Explanation:

Answer:

In the compond Mg(OH)_2, 20 atoms are present.

Explanation:

Answer:

D - g/mol

step by step method

Answer:

A dam like structure used to capture energy from masses of water moving in or out of a bay of rivers due to tidal force is called tidal barrage.

Explanation:

It may help you to solve question.

Answer: A volume of .5650 what? And what unit will be considered?

Answer:

The third one: [tex]CuSO_4[/tex]

Explanation:

Again you are going to want to look at a periodic table so you can determine the symbol of each atom.

The symbol for copper is Cu, the symbol for sulfur is S and the symbol for Oxygen.

There is 1 atom of copper in the compound

So we have Cu

There is 1 atom of sulfur in the compound

So we would have CuS

There are 4 atoms of oxygen in the compound

So we would have [tex]CuSO_4[/tex]

Note that the little number at the bottom left after each symbol indicates how many atoms of that element are in that compound.

Answer:

Frequency of spinal trait in the population = 0.11

Explanation:

Given:

Total spineless trait = 600

Number of spinal trait = 80

Find:

Frequency of spinal trait in the population

Computation:

Total population = Total spineless trait + Number of spinal trait

Total population = 600 + 80

Total population = 680

Frequency of spinal trait in the population = Number of spinal trait / Total population

Frequency of spinal trait in the population = 80 / 680

Frequency of spinal trait in the population = 0.11

Answer:

Solid and does not conduct electricity

Explanation:

[tex]\sf\bold{❍ Given:-}[/tex]

NaOH is dissolved in certain kilograms of solvent and molality of solution 0.5m.

Again , same among of NaOH is dissolved in 100 grams of solvent than initial , then molality becomes 0.625m.

$\space$

Now lets find the amount of NaOH and the initial mass of solvent.

Let,

$\space$

$\sf\bold{ ❍ We\:know,}$

$\sf{Molality(m)=}$ $\sf\dfrac{No.of\:moles\:of\:solute}{No.of\:solvent\:in\:kg}$

$\space$

$\sf\bold{Putting\:the\:formula:-}$

$\space$

$\sf\huge\underline\bold{ ❍Case:1}$

$\space$

$\longmapsto$ $\sf\small{0.5}$ $\sf\dfrac{x}{y}$

$\space$

$\longmapsto$ $\sf{0.5y = x }$

$\space$

$\longmapsto$ $\sf{multiply\:by\:2→ y = 2x}$

$\space$

$\sf\huge\underline\bold{ ❍Case:2}$

$\space$

$\longmapsto$ $\sf\small{0.625}$ $\sf\small\dfrac{x}{y}$ = $\sf\dfrac{x}{y=100g}$

$\space$

$\longmapsto$ $\sf\small{0.625}$ $\sf\dfrac{x}{y-100/1000kg}$ = $\sf\dfrac{x}{y-0.1kg}$

$\space$

$\longmapsto$ $\sf{0.625(y-0.1kg)=x}$

$\space$

$\longmapsto$ $\sf{0.625y-0.0625=x}$

$\space$

$\sf\small\bold{By\:putting\:the\:value\:of \:"x" we\: get:}$

$\space$

$\longmapsto$ $\sf{0.625(2x)-0.0625 = x}$

$\space$

$\longmapsto$ $\sf{1.25x 0.0625 = x}$

$\space$

$\longmapsto$ $\sf{1.25x - x = 0.0625}$

$\space$

$\longmapsto$ $\sf{0.25x = = 0.0625}$

$\space$

$\longmapsto$ $\sf\small{x=}$ $\sf\dfrac{0.0625}{0.25}$= $\sf\bold{x=0.25}$

$\space$

$\sf{So,y=2(x)=2\times0.25=}$ $\sf\bold{y=0.5}$

$\space$

$\sf\small{Initial\:mass\:of\:solvent:0.5kg=500g}$

$\space$

$\sf{Now,}$

Amount of NaOH=

$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=x\times molar\:mass}$

$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=0.25\times 40=10}$

$\space$

$\sf\underline{\underline{ ⚘ Hence,amount\:of\:NaOH=10kg}}$

_______________________________

Answer:

b) (i): 0.91 Amgstroms

(ii): 9.1 × 10^-11 Angstroms

(c): Volume = 20 Angstroms

Explanation:

• Let's first convert the units:

[tex]{ \rm{1 \:nanometre = 1 \times {10}^{ - 9} \: metres} } \\ { \rm{10 \: angstroms = 1 \times {10}^{ - 9} \: metres}} \\ { \rm{1 \: micrometer = 1 \times {10}^{ - 6} \: metres = 1000 \: nm}} \\ \\ { \rm{1 \: {nm}^{3} = 1000 \: {angstroms}^{3} }}[/tex]

Question (b)

[tex]{ \rm{radius = \frac{diameter}{2} }} \\ \\ { \rm{radius = \frac{0.182}{2} }} \\ \\ { \rm{radius = 0.091 \: nm}} \\ \\ { \mathfrak{ answer{ : { \rm{radius = (0.091 \times 10) \: angstroms}}}}} \\ \\ { \rm{radius = 0.91 \: angstroms}}[/tex]

[tex]{ \rm{radius = 0.091 \: nm}} \\ \\ { \rm{radius = 0.091 \times( 1 \times {10}^{ - 9} ) \: metres}} \\ \\ { \rm{radius = 9.1 \times {10}^{ - 11} \: m }}[/tex]

[tex]{ \rm{volume = (0.5 \times 0.2) \: nm \times 0.0002 \: micrometer}} \\ \\ { \rm{volume = 0.5nm \times 0.2nm \times (0.0002 \times 1000)nm}} \\ \\ { \rm{volume = 0.5 \times 0.2 \times 0.2 \: nm {}^{3} }} \\ \\ { \rm{volume = 0.02 \: nm {}^{3} }} \\ \\ { \rm{volume = (1000 \times 0.02) \: angstroms {}^{3} }} \\ \\ { \rm{volume = 20 \: angstroms}}[/tex]

The process of fertilization occurs externally in frogs.

A full growth of frog occurs when it passes through five stages of its life cycle. During a frog's metamorphosis, an egg will hatch and a tadpole appear in which the back legs emerge first, then front legs, and finally it become a full grown adult frog.

A frog's eggs are found in water because they do not have a hard protective shell like birds and reptiles. The frog's eggs are covered with a glycoprotein, which helps to keep the eggs moist so that's why the frog lays its eggs in water in order to prevent them from drying.

In most species of frogs, fertilization occurs externally. The male frog grabs the female's back and fertilizes the eggs as the female frog releases the eggs. Those eggs which receives the sperm will fertilized so we can conclude that the process of fertilization occurs externally in frogs.

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Answer:

it can occur between hydrogen and 3 other elements

Explanation:

These elements are:

Nitrogen

Oxygen

Flourine

Answer:

Explanation:

this is the answer hope it helps!(:

The chemical formula of pentanitrogen heptachloride is N₅Cl₇ as it has 5 nitrogen atoms and 7 chlorine atoms.

Chemical  formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols  of elements. It also makes use of brackets and subscripts.

Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form  is called empirical formula.

It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.

There are four types of chemical formula:

1)empirical formula

2) structural formula

3)condensed formula

4)molecular formula

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Answer

16g

Percent by mass=  mass of solute/mass of solution * 100

Explanation: work out the equation

Answer: carbon (C)

Explanation:

Answer:

A 1.732 g sample of iron is heated in air. It oxidizes to form a product with a mass of 2.205 g. What is the empirical formula of the product? FeO 4. Caffeine is made of 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen by mass.

Explanation:

The empirical formula of the product formed by the reaction of iron and oxygen is FeO.

Let's consider the following generic chemical equation:

Fe + O₂ ⇄ FexOy

According to the law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products. The mass of O₂ that reacted, and remains in the oxide is:

[tex]mFe + mO_2 = mFexOy\\mO_2 = mFexOy - mFe = 2.205 g - 1.732 g = 0.473 g[/tex]

The oxide has 1.732 g of Fe and 0.473 g of oxygen and a total mass of 2.205 g. To determine the empirical formula, we need to calculate the percent composition.

[tex]\%Fe = \frac{mFe}{mFexOy} \times 100 \% = \frac{1.732 g}{2.205 g} \times 100 \% = 78.55\%[/tex]

[tex]\%O = \frac{mO}{mFexOy} \times 100 \% = \frac{0.473 g}{2.205 g} \times 100 \% = 21.45\%[/tex]

Now, we will divide each percentage by the atomic mass of the element.

[tex]Fe: 78.55/55.85 = 1.406\\O: 21.45/16.00 = 1.340[/tex]

Finally, we divide both numbers by the smallest one.

[tex]Fe: 1.406/1.340 \approx 1 \\O: 1.340/1.340 = 1[/tex]

The empirical formula of the product is FeO.

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Answer: as the wavelength gets shorter, the energy increases; as the wavelength gets longer, the energy decreases. The greater the energy, the larger the frequency and the shorter (smaller) the wavelength.

Answer:

Just as wavelength and frequency are related to light, they are also related to energy. The shorter the wavelengths and higher the frequency corresponds with greater energy. So the longer the wavelengths and lower the frequency results in lower energy. The energy equation is E = hν.

Answer:High density

Explanation:

The metal doesn't remains gas at room tempreture, it doesn't have brittleness property and it is not poor conductor of electricity .But, it has high density .

Hope, it would be correct.

Answer:

6.75g of hydrogen will completely react with 54g of oxygen

Explanation:

Answer:

Explanation:

1.  H2O

Lewis Dot:  

See the attachment.

Note the б+ and б- signs on the H and O atoms, respectively.  Those represent the slightly positive and slightly negative sides of the water molecule.  Those slight charges on a single water molecule are attracted to their opposite charges on neighboring H2O molecules, as shown in the graphic.  This interaction is what gives water it's cohesive properties.

3.  The property of cohesion describes the ability of water molecules to be attracted to other water molecules. which allows water to be a "sticky" liquid.

The hydrogen bonds are attractions of electrostatic force.  They arise due to the difference in charge between the slightly positive hydrogen ion and the slightly negative oxygen ion. Hydrogen bonds form between neighboring hydrogen and oxygen atoms of adjacent water molecules. The attraction between individual water molecules creates a bond known as a hydrogen bond, and it is what gives water it's cohesiveness, or ability to support water spiders, paper clips, and produces a loud noise in the event of a belly flop in a pool (including the yelp from the swimmer).

4.  I'm not sure what is being asked for the two blanks.  Water is polar and dissolves salts (ionic compounds) and hydrophilic molecules (water-loving molecules).

Answer:

KI

Explanation:

From the question, we can see that a qualitative analysis of the compound shows that it has a lilac flame colour. The lilac flame colour corresponds to the potassium ion (K^+).

Again, the test of addition of HNO3(aq) and AgNO3(aq) to a solution is a test for halogens. If the result is a green precipitate, then the ion present is the iodide ion (I^-).

Hence, the compound must be KI.

Answer:

[tex]400 \div 6 \\ \\ [/tex]

Answer:

I DID HOW I KNOW . I HOPE IT WILL HELP YOU :D