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
kodGreya [7K]
3 years ago
14

What element in the fourth period is an exception to the Aufbau principle? a. Li c. Ca b. Cr d. Br

Chemistry
1 answer:
gulaghasi [49]3 years ago
4 0

The fourth period contains 18 elements, beginning with potassium and ending with krypton. As a rule, period 4 elements fill their 4s shells first, then their 3d and 4p shells, in that order; however, there are exceptions, such as chromium.

Cr. I think

You might be interested in
Mass is measured in ____________, and weight is measured in ______________. A) kilograms, grams B) grams, kilograms C) newtons,
frez [133]
I'm pretty sure the answer is letter D.
8 0
3 years ago
Read 2 more answers
1. (8pt) Using dimensional analysis convert 600.0 calories into kilojoules
Ivanshal [37]

Answer:

1. 2.510kJ  

2. Q = 1.5 kJ

Explanation:

Hello there!

In this case, according to the given information for this calorimetry problem, we can proceed as follows:

1. Here, we consider the following equivalence statement for converting from calories to joules and from joules to kilojoules:

1cal=4.184J\\\\1kJ=1000J

Then, we perform the conversion as follows:

600.0cal*\frac{4.184J}{1cal}*\frac{1kJ}{1000J}=2.510kJ

2. Here, we use the general heat equation:

Q=mC(T_2-T_1)

And we plug in the given mass, specific heat and initial and final temperature to obtain:

Q=236g*0.24\frac{J}{g\°C} (34.9\°C-8.5\°C)\\\\Q=1495.3J*\frac{1kJ}{1000J} \\\\Q=1.5kJ

Regards!

7 0
2 years ago
!!!!!PLEASE HELP!!!!!
ollegr [7]

Answer:

Difference in the potential energy of the reactants and products

Explanation:

 

The products have a lower potential energy than the reactants, and the sign of ΔH is negative. In an endothermic reaction, energy is absorbed. The products have a higher potential energy than the reactants, and the sign of ΔH is positive.

3 0
3 years ago
How is the number of electrons in an element determined?
elixir [45]

The number of protons, neutrons, and electrons in an atom can be determined from a set of simple rules. The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons.

3 0
2 years ago
Read 2 more answers
Which element above has 6 protons in its nucleus?
Vinil7 [7]
B. carbon because it's atomic number is 6
5 0
3 years ago
Read 2 more answers
Other questions:
  • Mass of water using isotopes? The water found on Earth is almost entirely made up of the ^1H and ^{16}O isotopes for a formula o
    15·2 answers
  • The mass-to charge ratio of the proton is found to be
    8·1 answer
  • The reaction of 2h2+o2-->2H2o + heat is
    15·2 answers
  • Table salt is considered a(n) ______________ because it conducts electricity in water. A) electrolyte B) electrolysis C) nonelec
    12·2 answers
  • What is the most stable condition for an atom
    5·2 answers
  • Please help!!
    8·1 answer
  • When ethyl acetoacetate (CH3COCH2CO2CH2CH3) is treated with one equivalent of CH3MgBr, a gas is evolved from the reaction mixtur
    8·1 answer
  • Properties of alloy​
    10·2 answers
  • What does ozone do to make life on earth possible?
    15·1 answer
  • 2. When iron rusts what is it reacting with?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!