Which of these determines the identity of an element?

• A. Number of electrons

• B. Number of protons

• C. Number of energy levels

• D. Number of neutrons

Sodium is an element found in table salt. It contains 11 protons and 12 neutrons. How many electrons are found in a neutral atom of sodium?

• A. 23

• B. 12

• C. 11

• D. 1

Tags

NGSS.MS-PS1-1

Elements are described as pure substances because

• A. they are all found in nature

• B. they cannot be separated into parts by physical means

• C. they have no charge

• D. they can be produced in a laboratory

The nucleus of an atom contains

• A. only neutrons

• B. protons and electrons

• C. protons and neutrons

• D. only electrons

Tags

NGSS.MS-PS1-1

How many protons does nickel have?

• A. 31

• B. 28

• C. 59

• D. 3

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NGSS.MS-PS1-1

Based on the description in the table, what is the atomic mass of nickel?

• 31

• 28

• 59

• 3

Which statement about matter below is true?

• Matter makes up things that only we can see

• Everything in the universe is made up of matter

• The smallest building blocks of matter are protons

• Atoms are the building blocks of matter, and they are made up of only protons and electrons

Tags

NGSS.MS-PS1-1

How do you find how many protons an atom has?

• Look at the atomic mass

• Look at the atomic number

• Look at the nucleus

• It depends on when it was discovered

What is the best way to identify an element?

• By the amount of protons it has

• By the amount of neutrons it has

• By the size of the nucleus

• By its date of discovery

If I have an atomic number of 18 and an atomic mass of 39, how many protons does this element have?

• 39

• 21

• 18

• 57

Tags

NGSS.MS-PS1-1