The circulatory system works with other systems to (select all that apply)

What is the main difference between ionic<br> compounds and molecular compounds?

Sophie [7]

Answer:

¨molecular compounds are formed by the sharing of electrons, and ionic compounds are formed by the transfer of electrons¨

Explanation:

3 0

3 years ago

The atomic number of an element is the total number of which particles in the nucleus?

VARVARA [1.3K]

An atom of element has there subatomic particles namely, proton, electron and neutron. Here, for a neutral atom, number of proton is equal to number of electron (this is not in the case of ions), this is equal to atomic number of an atom. In an atom, nucleus contains protons and neutrons which is responsible for mass of the atom and electrons move around nucleus in fixed orbits. Thus, atomic mass of an atom is equal to sum of number of protons and neutrons.

Option (b): Proton is the particle in nucleus of an atom, whose total number is equal to atomic number of that atom.

(4) Option (b): Atoms of same element have same atomic number because mass number can be different for different isotopes of atom. Since, atomic number is equal to number of protons, thus, number of protons are same for all atoms of the same element.

(5) Option (d): Isotopes are defined as atoms of same element with same atomic number but different mass number. Thus, correct option is (d) mass numbers.

4 0

3 years ago

Read 2 more answers

0.5mol/dm3 hydrochloric acid is added gradually to a flask containing 20cm3 of 2 mol/ dm3 sodium hydroxide solution.

sweet-ann [11.9K]

Answer:

The answer is B which is 40

7 0

2 years ago

Two samples of potassium iodide are decomposed into their constituent elements. The first sample produced 13.0g of potassium and

Leona [35]

Answer:

79.43kg

Explanation:

To adequately solve this problem, we should know the law of constant composition. This is a pointer to the fact that no matter the type of sample, the percentage compositions of potassium and iodine still remains the same. We can use these masses to get a formula and we would know the percentage compositions in whatever mass we are dealing with.

First of all, we add the masses in the first sample. 13 + 42.3 = 55.3

Hence, the percentage composition of the potassium is 13/55.3 * 100 = 23.51%

The percentage composition of the iodine is = 100 - 23.51 = 76.49%

Now, we need to get the formula of the compound. We can get this by dividing the percentage compositions with the atomic masses. The atomic mass of potassium and iodine is 39 and 127 respectively.

Potassium = 23.51/39 =0.603

Iodine = 76.49/127 = 0.602

We then divide by the smaller value to get the formula and this shoes our formula is KI

We can see they have a ratio of 1 to 1, meaning one atom of potassium to one atom of iodine. This further confirms the percentage compositions of 23.5 to 76.5

Now to get the mass of iodine yielded, let us say the mass is xkg

This means x/(x + 24.4) * 100 = 76.5

100x = 76.5( x + 24.4)

100x = 76.5x + 1866.6

100x - 76.5x = 1866.6

23.5x = 1866.6

x = 1866.6/23.5 = 79.43kg

4 0

3 years ago

A sample of 35.1 g of methane gas has a volume of 5.20 l at a pressure of 2.70 atm. calculate the temperature of the gas.

melisa1 [442]

We can use the ideal gas equation to determine the temperature with the given conditions of mass of the gas, volume, and pressure. The equation is expressed
PV=nRT where n is the number of moles equal to mass / molar mass of gas. Substituting the given conditions with R = 0.0521 L atm/mol K we can find the temperature

6 0

3 years ago