What can group numbers on the periodic table help you determine?

Sterling silver contains silver and copper metals. if a sterling silver chain contains 17.6g of silver and 2.40g of copper, what

Bogdan [553]

Answer:- 0.88

Solution:- Masses of silver and copper metals are given and we are asked to calculate the percentage of silver in the alloy.

mass percent of Ag = $(\frac{mass of Ag}{mass of alloy})*100$

Mass of Ag = 17.6 g

mass of Cu = 2.40 g

mass of alloy = 17.6 g + 2.40 g = 20.0 g

Let's plug in the values in the formula:

mass percentage of Ag = $(\frac{17.6}{20.0})*100$

mass percentage of Ag = 88%

So, the mass percentage of silver in sterling silver is 88% and in decimal form it is 0.88.

7 0

3 years ago

Figure 4, Future climate prediction for North America. By 2100, the low-emissions scenario (550 ppm CO2, left) and high-emission

ella [17]

Answer:

Las Vegas is expected to recieve less precipitation

6 0

2 years ago

What does an electromagnet create? a. electricity b. magnet c. neutrons

sdas [7]

Answer:

Electromagnet creates electricity.

Explanation:

4 0

3 years ago

Read 2 more answers

An ionic bond forms when atoms blank electrons

8_murik_8 [283]

Answer:

An ionic bond forms when atoms transfer electrons.

Explanation:

Ionic bonds are formed when atoms transfer electrons. (In contrast, covalent bonds are formed when atoms share electrons.)

There's a distinction between the two: when two atoms react to form an ionic bond, one atom would completely lose one electron, while the other would completely gain that electron. The atom that loses the electron becomes a positively-charged ion called a cation, whereas the atom that gains the electron becomes a negatively-charged ion called an anion.

For example, consider the reaction between a sodium $\rm Na$ atom and a chlorine $\rm Cl$ atom: $\rm Na + Cl \to NaCl$ .

When the sodium atom and the chlorine atom encounter, the sodium atom would lose one electron to form a positively-charged sodium ion, $\rm Na^{+}$ . The chlorine atom would gain that electron to form a negatively-charged chlorine ion $\rm Cl^{-}$ .

These two ions will readily attract each other because of the opposite electrostatic charges on them. This electrostatic attraction (between two ions of opposite charges) is an ionic bond.

Overall, it would appear as if the sodium $\rm Na$ atom transferred an electron to the chlorine $\rm Cl$ atom to form an ionic bond.

In contrast, when two atoms react to form a covalent bond, they share electrons without giving any away completely. Therefore, it is possible to break certain covalent bonds apart (using a beam of laser, for example) and obtain neutral atoms.

On the other hand, when an ionic bond was broken, the result would be two charged ions- not necessarily two neutral atoms. The electron transfer could not be reversed by simply breaking the bond.

For example, when table salt $\rm NaCl$ is melted (at a very high temperature,) the ionic bond between the sodium ions and chloride ions would (mostly) be broken. However, doing so would only generate a mixture of $\rm Na^{+}$ and $\rm Cl^{-}$ ions- not sodium and chlorine atoms.

7 0

2 years ago

Propane is often used to heat homes. The combustion of propane follows the following reaction: C3H8(g) + 5O2(g)  3CO2 (g) + 4H

swat32

Answer:

To release 7563 kJ of heat, we need to burn 163.17 grams of propane

Explanation:

Step 1: Data given

C3H8 + 5O2 -----------> 3CO2 + 4H2O ΔH° = –2044 kJ

This means every mole C3H8

Every mole of C3H8 produces 2044 kJ of heat when it burns (ΔH° is negative because it's an exothermic reaction)

Step 2: Calculate the number of moles to produce 7563 kJ of heat

1 mol = 2044 kJ

x mol = 7563 kJ

x = 7563/2044 = 3.70 moles

To produce 7563 kJ of heat we have to burn 3.70 moles of C3H8

Step 3: Calculate mass of propane

Mass propane = moles * Molar mass

Mass propane = 3.70 moles * 44.1 g/mol

Mass propane = 163.17 grams

To release 7563 kJ of heat, we need to burn 163.17 grams of propane

7 0

3 years ago