1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Luda [366]
3 years ago
13

How many isotopes does the element with atomic number 21 have?

Chemistry
1 answer:
ycow [4]3 years ago
7 0

Answer: 13 isotopes

Explanation: Scandium is the element with an atomic number of 21, there is only one naturally occuring isotope of Scandium

You might be interested in
How many atoms will there be in 5.00 g of gold. (Use ^ to show the exponent in scientific notation. For example, 4 X 1011 should
gayaneshka [121]

Answer:

1.53x10^22 atoms of Au

Explanation:

To find the atoms of gold we need first, to convert the mass of gold to moles using molar mass of gold (196.97g/mol). Then, these moles must be converted to number of atoms based on definition of moles (1 mole = 6.022x10²³ atoms).

<em>Moles Au:</em>

5.00g Au * (1mol / 196.97g) = 0.0254 moles of Au

<em>Atoms of Au:</em>

0.0254 moles * (6.022x10²³ atoms / 1 mole) =

<h3>1.53x10^22 atoms of Au</h3>
3 0
3 years ago
37.9 grams of an unknown substance undergoes a temperature increase of
jenyasd209 [6]

Answer:

1.023 J / g °C

Explanation:

m = 37.9 grams

ΔT = 25.0*C

H = 969 J

c = ?

The equation relating these equation is;

H = mcΔT

making c subject of formulae;

c = H / mΔT

c = 969 J / (37.9 g * 25.0*C)

Upon solving;

c = 1.023 J / g °C

4 0
3 years ago
A. When glucose molecules link up what substance do they form?
alexgriva [62]

Answer:

Explanation: b

7 0
3 years ago
Read 2 more answers
What is the length in inches (in) of a 100-meter soccer field?
max2010maxim [7]

Answer:

3937 inches

Explanation:

1m = 39.37 inches.

However, we want to know how long a 100m soccer field is, so we have to times the value for 1m by 100.

Therefore, an 100m soccer field = 100 x 39.37 = 3937 inches

7 0
3 years ago
instrucions classify the following reactions as synthesis, decomposition,single replacement, double replacement, or combustion.
My name is Ann [436]

Answer:

There are no specific equations but here what i can give you:

1. Synthesis -- A synthesis reaction is a chemical change in which two or more substances react to form a single new substance.

In all synthesis reactions, there is a single product that is a compound!

2. Decomposition -- A decomposition reaction is a chemical change in which a single compound breaks down into two or more simpler products. (This is the opposite of synthesis reactions!)

Most decomposition reactions require energy in the form of heat, light, and electricity.

3. Single Replacement -- A single-replacement reaction is a chemical change in which one element replaces a second element in a compound. You can identify a single-replacement reaction by noting that both the reactants and the products consist of an element and a compound.

4. Double Replacement -- A double-replacement reaction is a chemical change involving an exchange of positive ions between two compounds.

For a double replacement reactions to occur, one of the following is usually true:

- One of the products is only slightly soluble and precipitates from solutions.

- One of the products is a gas.

- One product is a molecular compound such as water.

5. Combustion -- A combustion reactions is a chemical change in which an element or a compound reacts with oxygen, often producing energy in the form of heat or light.

A combustion reactant always involves oxygen as a reactant. (If the supply of oxygen is limited, then the combustion will not be complete.)

The other reactant is a hydrocarbon, which is a compound composed of hydrogen and carbon and the complete combustion of a hydrocarbon produces CO2 and H2O.

Hydrocarbons include methane, propane, and butane.

I really hope this helps you!

3 0
3 years ago
Other questions:
  • A 12.8 g piece of aluminum (which has a molar heat capacity of 24.03 j/°c·mol) is heated to 82.4°c and dropped into a calorimete
    13·1 answer
  • Visible light represents a very small portion of the electromagnetic spectrum. Radiation to the left in the image, such as micro
    12·2 answers
  • Which electromagnetic wave has the longest wavelength?
    14·1 answer
  • How many grams and what is the limiting reactent?
    11·1 answer
  • Is slime a liquid or solid?
    5·2 answers
  • Be sure to answer all parts. What is the [H3O+] and the pH of a buffer that consists of 0.26 M HNO2 and 0.89 M KNO2? (K, of HNO2
    9·1 answer
  • Dalton's Law of Partial pressure: The total pressure of a gas mixture is the sum of the partial pressures of each gas . Therefor
    5·2 answers
  • 4.5 X 6.02214076 x 10^23
    5·1 answer
  • Calculate the amount of mole of gas which occupies 250cm at S.T.P ​
    15·1 answer
  • Which of the following is not good conductor of heat?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!