All categories

3 years ago

An atom has 27 protons and 32 neutrons. Which of the following symbols is correct for this atom?

1 answer:

6 0

59Co
To identify the element, look at the atomic number, which is the amount of protons. This is cobalt.
The notation used above to write the element is mass number-chemical symbol, and so to find the mass number, simply add the number of protons to the number of neutrons. This gives you 59. Therefore, the correct symbol is 59Co

You might be interested in

In redox reactions, electrons are _____.

ludmilkaskok [199]

In redox reaction electrons are transferred

Redox reaction involve both reducing of b agent and oxidizing agent. reducing agent acts as electrons donor while oxidizing agent acts as electron acceptor
for example formation of Hydrogen fluoride (HF)

that is H2 + F2 = HF

by breaking the equation

H2 = 2 H^+ 2e-
F2 + 2e= 2f-

hydrogen move from oxidation from zero( 0 )to positive one ( +1 )therefore hydrogen is oxidized. Fluorine move from oxidation state of zero(0) to oxidation state of negative one(-1) therefore fluorine is reduced.

6 0

3 years ago

Explain with examples following characteristics of chemical reactions: a. Change of colour b. Evolution of gas c. Change of smel

Andrei [34K]

Answer:

Explanation:

a. change of colour:

A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. The products have different molecular structures than the reactants. Different atoms and molecules radiate different colours of light. Hence, there usually is a change in colour during a chemical reaction.

Eg: copper reactions with the elements

b. Evolution of gas:

A gas evolution reaction is a chemical reaction in which one of the end products is a gas such as oxygen or carbon dioxide.

Eg: ammonium hydroxide breaks down to water and ammonia gas.

c. Change of smell :

Production of an Odor Some chemical changes produce new smells. ... The formation of gas bubbles is another indicator that a chemical change may have occured.

Eg: The chemical change that occurs when an egg is rotting produces the smell of sulfur.

d. Change of state:

A chemical reaction is a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products.

Eg: candle wax (solid) melts initially to produce molten wax (liquid)

plz mark as brainliest!!!!

4 0

4 years ago

Each of the three known isotopes of hydrogen has blank protons in the nucleus

Vilka [71]

Answer:

They each have one single proton (Z = 1), but differ in the number of their neutrons. Hydrogen has no neutron, deuterium has one, and tritium has two neutrons. The isotopes of hydrogen have, respectively, mass numbers of one, two, and three.

4 0

3 years ago

Which statement about subatomic particles is true?

Kruka [31]

The correct statement about subatomic particles is Electrons are the subatomic particles with the smallest mass.

The mass of protons and neutrons which are considered as 1 unit of mass of atoms is approximately 1836 times the mass of the electron

$\boxed {\boxed {\bold {Further ~ explanation}}}$

Atoms are composed of 3 types of basic particles namely protons, electrons, and neutrons

The mass of this basic particle is expressed in units of atomic mass

This atomic unit uses the standard atomic mass, that is, the C-12 isotope

1 atom C-12 = 12 atomic mass units

1 atomic mass unit = 1/12 x mass 1 C-12 atom

1 unit of atomic mass = 1.66.10⁻²⁴

the mass of each basic particle in atomic mass units is:

electron mass = 9.11.10⁻²⁸

proton mass = 1.6726.10⁻²⁴

neutron mass = 1,675.10⁻²⁴

The proton mass is considered to be equal to 1 atomic mass unit and a neutron which is also considered to be equal to 1 atomic mass unit

The charge of 1 proton is equal to a charge of 1 electron but has a different sign

The proton is positively charged (+1), the electron is negatively charged (-1). and neutrons not charged (neutral)

For a charge of 1 electron = e = 1.66.10⁻¹⁹ coulomb

Whereas the neutron charge = 0

Let's look at the answer choices

1. Protons are the only subatomic particles to have a charge.

This statement is wrong because in the nucleus there are electrons charged -

2. Electrons are the subatomic particles with the smallest mass.

The statement is true because the mass of protons and neutrons which are considered as 1 unit of mass of atoms is approximately 1836 times the mass of the electron

3. Neutrons orbit the nucleus of the atom.

This statement is wrong.

It can be explained by the Bohr atomic model, where electrons circulate the nucleus on a particular path so that electrons are not attracted to the nucleus.

4. Subatomic particles all have the same mass

This statement is wrong because the mass of protons and neutrons is the same while the electron mass is smaller

So the correct statement about subatomic particles is Electrons are the subatomic particles with the smallest mass.

$\boxed {\boxed{\bold {Learn ~ more}}}$

The subatomic particle

brainly.com/question/2224691

the main difference between the Bohr model of the atom and the rutherford model.

brainly.com/question/1528920

The equation between Bohr and Rutherford models

brainly.com/question/1184332

the hypothesis of Thomson's atomic model

brainly.com/question/10943651

Keywords: atomic model, Bohr, atoms, protons, electrons, atomic, neutrons

5 0

3 years ago

Read 2 more answers

In a study designed to prepare new gasoline-resistant coatings, a polymer chemist dissolves 6.143 g poly(vinyl alcohol) in enoug

Ghella [55]

Answer:

MM = 5,521.54 g/mol

Explanation:

To solve this, we need to use the expression for osmotic pressure which is the following:

π = MRT (1)

Where:

M: Concentration of the solution

R: gas constant (0.082 L atm/ mol K

T: temperature in K

25 °C in Kelvin is: 25 + 273.15 = 298.15 K

Now, we do not have the concentration of the solution, but we do have the mass. and the concentration can be expressed in terms of mass, molar mass and volume:

Concentration (M) is:

M = n/V (2)

and n (moles) is:

n = m/MM (3)

Therefore, if we replace (2) and (3) in (1) we have:

π = mRT/V*MM

Solving for MM we have:

MM = mRT/πV (4)

All we have to do now, is replace the given data and we should get the value of the molar mass:

MM = 6.143 * 0.082 * 298.15 / 0.1 * 0.272

MM = 150.1859 / 0.0272

<em>This is the molar mass.</em>

7 0

3 years ago